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Clinical trials are the backbone of medical scientific research. However, this experimental strategy has some drawbacks. We focused on two issues: (a) The internal validity ensured by clinical trial procedures does not necessarily allow for generalization of efficacy results to causal claims about effectiveness in the population. (b) Statistical significance does not imply clinical or practical significance; p-values should be supplemented with effect size (ES) estimators and an interpretation of the magnitude of the effects found. We conducted a systematic review (from 2000 to 2020) on Scopus, PubMed, and four ProQuest databases, including PsycINFO. We searched for experimental studies with significant effects of pharmacological treatments on depressive symptoms, measured with a specific scale for depression. We assessed the claims of effectiveness, and reporting and interpreting of effect sizes in a small, unbiased sample of clinical trials (n = 10). Only 30% of the studies acknowledged that efficacy does not necessarily translate to effectiveness. Only 20% reported ES indices, and only 40% interpreted the magnitude of their findings. We encourage reflection on the applicability of results derived from clinical trials about the efficacy of antidepressant treatments, which often influence daily clinical decision-making. Comparing experimental results of antidepressants with supplementary observational studies can provide clinicians with greater flexibility in prescribing medication based on patient characteristics. Furthermore, the ES of a treatment should be considered, as treatments with a small effect may be worthwhile in certain circumstances, while treatments with a large effect may be justified despite additional costs or complications. Therefore, researchers are encouraged to report and interpret ES and explicitly discuss the suitability of their sample for the clinical population to which the antidepressant treatment Will be applied., Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub, Descuento UCM

Introduction An increasing number of studies are using magnetoencephalography (MEG) to study dementia. Here we define a common methodological framework for MEG resting-state acquisition and analysis to facilitate the pooling of data from different sites. Methods Two groups of patients with mild cognitive impairment (MCI, n = 84) and healthy controls (n = 84) were combined from three sites, and site and group differences inspected in terms of power spectra and functional connectivity. Classification accuracy for MCI versus controls was compared across three different types of MEG analyses, and compared with classification based on structural MRI. Results The spectral analyses confirmed frequency-specific differences in patients with MCI, both in power and connectivity patterns, with highest classification accuracy from connectivity. Critically, site acquisition differences did not dominate the results. Discussion This work provides detailed protocols and analyses that are sensitive to cognitive impairment, and that will enable standardized data sharing to facilitate large-scale collaborative projects., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Neurofeedback is a neuronal self-regulation technique that teaches people to modulate their brain frequencies using visual and auditory reinforcements presented on a computer screen. To assess the effect of neurofeedback training in children with ADHD as far as improved attention and impulse control, and analyze whether or not there are differences between the inattentive and hyperactive subtypes. Fifty children diagnosed with ADHD participated in the study: 14 comprised the control group, and 36 the experimental group (16 with the inattentive ADHD subtype, 20 with the hyperactive ADHD subtype). Attention and impulse control were assessed using the Integrated Visual Auditory CPT (IVA/CPT). Results indicated that the predominantly inattentive group showed significant differences on the Control Scale (p = .023, d = 1.31) and the Attention Scale (p < .01, d = 1.89) of the IVA/CPT; meanwhile the predominantly hyperactive group showed significant improvement on the Control Scale ( p = .016, d = 1.21). The control group exhibited no significant differences on either of the two scales ( p > .5). In terms of theta/beta ratio, no significant differences were detected ( p = .10) between ADHD subtypes. The findings suggest that neurofeedback training using the theta/beta protocol was more effective in the predominantly inattentive subset of individuals with ADHD., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Given the importance of attention and executive functions in children's behavior, programs directed to improve these processes are of interest. Nexxo-training combines the use of the Nexxo touchscreen application (go/no-go and stop signal tasks) with procedural metacognitive strategies. The present paper reports a test of Nexxo's impact on children aged 6–7 and 8–9 years. We conducted a randomized active-controlled trial involving 108 typically-developing children: 1st grade (N = 61, M = 6.46 years, SD = 0.35) and 3rd grade (N = 47, M = 8.5 years, SD = 0.27), randomly assigned to: (1) experimental, (2) active-control, or (3) passive-control groups. A 2-month follow-up was carried out after the intervention. The 3rd grade experimental group displayed a significant reduction in attentional problems at follow-up compared to both control groups. Executive Function problems were also reduced at follow-up in the experimental group. Participants in this group improved in Supervision (self-monitoring) at post-intervention and follow-up compared to passive-controls. Although group effect was not significant at t1, it was significant at post measures in experimental group compared to passivecontrols. Nexxo-training revealed a trend-level improvement in attention and executive functions for children in the 3rd grade., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Objective This study analyzed variability in cerebral blood flow velocity (CBFV) and its association with emotional, clinical and functional variables and medication use in fibromyalgia syndrome (FMS). Methods Using transcranial Doppler sonography, CBFV were bilaterally recorded in the anterior (ACA) and middle (MCA) cerebral arteries of 44 FMS patients and 31 healthy individuals during a 5-min resting period. Participants also completed questionnaires assessing pain, fatigue, insomnia, anxiety, depression and health-related quality of life (HRQoL). Results Fast Fourier transformation revealed a spectral profile with four components: (1) a first very low frequency (VLF) component with the highest amplitude at 0.0024 Hz; (2) a second VLF component around 0.01-to-0.025 Hz; (3) a low frequency (LF) component from 0.075-to- 0.11 Hz; and (4) a high frequency (HF) component with the lowest amplitude from 0.25-to- 0.35 Hz. Compared to controls, FMS patients exhibited lower LF and HF CBFV variability in the MCAs (p < .005) and right ACA (p = .03), but higher variability at the first right MCA (p = .04) and left ACA (p = .005) VLF components. Emotional, clinical and functional variables were inversely related to LF and HF CBFV variability (r -.24, p .05). However, associations for the first VLF component were positive (r .28, p .05). While patients medication use was associated with lower CBFV variability, comorbid depression and anxiety disorders were unrelated to variability. Conclusions Lower CBFV variability in the LF and HF ranges were observed in FMS, suggesting impaired coordination of cerebral regulatory systems. CBFV variability was differentially associated with clinical variables as a function of time-scale, with short-term variability being related to better clinical outcomes. CBFV variability analysis may be a promising tool to characterize FMS pathology and it impact on facets of HRQoL., Depto. de Psicología Social, del Trabajo y Diferencial, Fac. de Psicología, TRUE, pub

Background Alzheimer’s disease (AD) prevalence is rapidly growing as worldwide populations grow older. Available treatments have failed to slow down disease progression, thus increasing research focus towards early or preclinical stages of the disease. Subjective cognitive decline (SCD) is known to increase the risk of developing AD and several other negative outcomes. However, it is still very scarcely characterized and there is no neurophysiological study devoted to its individual classification which could improve targeted sample recruitment for clinical trials. Methods Two hundred fifty-two older adults (70 healthy controls, 91 SCD, and 91 MCI) underwent a magnetoencephalography scan. Alpha relative power in the source space was employed to train a LASSO classifier and applied to distinguish between healthy controls and SCD. Moreover, MCI participants were used to further validate the previously trained algorithm. Results The classifier was significantly associated to SCD with an AUC of 0.81 in the whole sample. After randomly splitting the sample in 2/3 for discovery and 1/3 for validation, the newly trained classifier was also able to correctly classify SCD individuals with an AUC of 0.75 in the validation sample. The regions selected by the algorithm included medial frontal, temporal, and occipital areas. The algorithm trained to select SCD individuals was also significantly associated to MCI diagnostic. Conclusions According to our results, magnetoencephalography could be a useful tool for distinguishing individuals with SCD and healthy older adults without cognitive concerns. Furthermore, our classifier showed good external validity, being not only successful for an unseen SCD sample, but also in a different population with MCI cases. This supports its utility in the context of preclinical dementia. These findings highlight the potential applications of electrophysiological techniques to improve sample recruitment at the individual level in the context of c, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Robust identification and tracking of the pupil provides key information that can be used in several applications such as controlling gaze-based HMIs (human machine interfaces), designing new diagnostic tools for brain diseases, improving driver safety, detecting drowsiness, performing cognitive research, among others. We propose a deep convolutional neural network for eye-tracking based on atrous convolutions and spatial pyramids. DeepEye is able to handle real world problems such as varying illumination, blurring and reflections. The proposed network was trained and evaluated on 94,000 images taken from 24 data sets recorded in real world scenarios. DeepEye outperforms previous eye-tracking methods tested with these data sets. It improves the results of the current state of the art in a 26%, achieving an accuracy of more than 70% in almost every data set in terms of percentage of pupils detected with a distance error lower than 5 pixels., Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Wilhelm Wundt and Sigmund Freud are the founders of psychological modern thought. The concept citation context method was used to analyse the mutual influence. The results show that Wundt's work was important to explain the hallucinatory character of the dream. On the other side, Wundt's quotations about Freud show his refusal to recognize the unconscious as a valid hypothesis to explain any kind of psychological phenomenon. In conclusion, the Freudian unconscious is the excess of the lack of the Wundt ́s system to explain phenomena that exceed the study of normal consciousness., Wilhelm Wundt y Sigmund Freud son los fundadores del pensamiento psicológico moderno. Para analizar la influencia mutua se utilizó el método del contexto de las citas. Los resultados muestran que la obra de Wundt fue importante para explicar el carácter alucinatorio del sueño. Por otro lado, las citas de Wundt sobre Freud muestran su rechazo a reconocer el inconsciente como una hipótesis válida para explicar cualquier tipo de fenómeno psicológico. En conclusión, el inconsciente freudiano es el exceso de la incapacidad del sistema de Wundt para explicar los fenómenos que exceden el estudio de la conciencia normal.

A pioneering study by J. M. Harris and A. J. Parker (1995) found that disparity judgments using random-dot stereograms were better for stimuli composed of mixed bright and dark dots than when the dots were all bright or all dark. They attribute this to an improvement in stereo correspondence. This result is hard to explain within current models of how stereo correspondence is achieved. However, their experiment varied task difficulty by adding disparity noise. We wondered if this might challenge mechanisms subsequent to the solution of the correspondence problem rather than mechanisms that solve the correspondence problem itself. If so, this would avoid the need to modify current models of stereo correspondence. We therefore repeated Harris and Parker's experiment using interocular decorrelation to vary task difficulty. This technique is believed to probe stereo correspondence more specifically. We observed the efficiency increase reported by Harris and Parker for mixed-polarity dots both using their original technique of disparity noise and using interocular decorrelation. We show that this effect cannot be accounted for by the stereo energy or by simple modifications of it. Our results confirm Harris and Parker's original conclusion that mixed-polarity dots specifically benefit stereo correspondence and point up the challenge to current models of this process., The Royal Society, Medical Research Council, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Proportion correct in two-alternative forcedchoice (2AFC) detection tasks often varies when the stimulus is presented in the first or in the second interval.Reanalysis of published data reveals that these order effects (or interval bias) are strong and prevalent, refuting the standard difference model of signal detection theory. Order effects are commonly regarded as evidence that observers use an off-center criterion under the difference model with bias. We consider an alternative difference model with indecision whereby observers are occasionally undecided and guess with some bias toward one of the response options. Whether or not the data show order effects, the two models fit 2AFC data indistinguishably, but they yield meaningfully different estimates of sensory parameters. Under indeterminacy as to which model governs 2AFC performance, parameter estimates are suspect and potentially misleading. The indeterminacy can be circumvented by modifying the response format so that observers can express indecision when needed. Reanalysis of published data collected in this way lends support to the indecision model. We illustrate alternative approaches to fitting psychometric functions under the indecision model and discuss designs for 2AFC experiments that improve the accuracy of parameter estimates, whether or not order effects are apparent in the data., Ministerio de Ciencia e Innovación (MICINN), Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Vertical disparities influence the perception of 3D depth, but little is known about the neuronal mechanisms underlying this. One possibility is that these perceptual effects are mediated by an explicit encoding of two-dimensional disparity. Recently, J. C. A. Read and B. G. Cumming (2006) pointed out that current psychophysical and physiological evidence is consistent with a much more economical one-dimensional encoding. Almost all relevant information about vertical disparity could in theory be extracted from the activity of purely horizontal-disparity sensors. Read and Cumming demonstrated that such a 1D system would experience Ogle's induced effect, a famous illusion produced by vertical disparity. Here, we test whether the brain employs this 1D encoding, using a version of the induced effect stimulus that simulates the viewing geometry at infinity and thus removes the cues which are otherwise available to the 1D model. This condition was compared to the standard induced effect stimulus, presented on a frontoparallel screen at finite viewing distance. We show that the induced effects experienced under the two conditions are indistinguishable. This rules out the 1D model proposed by Read and Cumming and shows that vertical disparity, including sign, must be explicitly encoded across the visual field., Royal Society, Medical Research Council, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Se muestra la relación entre Simarro y la Escuela Histológica Española de Cajal, señalando la génesis de la dedicación cajaliana a la Histología -su inquietud por la Psicología-, el trayecto científico de Simarro, dedicado a la Histología como fundamento de la Neuropsicología y la Psicología, el encuentro de ambos en 1887, en el que Simarro ofrece a Cajal un nuevo método de tinción del sistema nervioso que le va a permitir su labor y sus trascendentales descubrimientos, la prolongación de la obra de Simarro, en fin, a través de sus discípulos, también colaboradores de Cajal., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

El objetivo del presente trabajo consistió en analizar la capacidad de personas con discapacidad intelectual ligera y moderada para identificar a personas desconocidas vistas durante un periodo de tiempo breve y evaluar los factores que pudieran facilitar la tarea minimizando los errores. Para ello, se presentó a dos grupos de sujetos, con discapacidad y control, una fotografía de una persona que tras una tarea distractora deberían identificar en dos ruedas de seis fotografías (una de objetivo ausente y otra de objetivo presente). Cada sujeto realizó cuatro ensayos, dos con fotografías de hombres y otras dos con fotografías de mujeres. Los resultados mostraron que las personas con discapacidad intelectual en comparación con los sujetos control cometían menos aciertos y más falsas alarmas y discriminaban peor las caras (d’), aunque con pocas diferencias en el criterio de respuesta (ß). La relación entre rendimiento y CI resultó significativa para algunos de los tipos de respuesta. [ABSTRACT] The aim of this study was to analyze the unfamiliar face recognition ability of people with mild and moderate intellectual disabilities and assess factors that might facilitate the task while minimizing errors. For this purpose, two groups had to recognize in two lineups with six photographs each (one present-target and one absent-target). Each subject performed four trials, two with pictures of men and two with women. Analysis of the results suggests that people with intellectual disabilities compared with control group made fewer hits and more false alarms and discriminate faces worst (d’), but with few differences in the response bias (ß). The relationship between unfamiliar face recognition performance and IQ was significant in some types of responses., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Se señala la fuerte gravitación que en la infancia y adolescencia de Luis Simarro tuvieron las formas de vida y la mentalidad románticas, vigentes en la España de los años cincuenta y sesenta del siglo XIX. Será la época de la Restauración la que preste contexto histórico a su vida y a su obra: determinados momentos de la trayectoria biográfica de Simarro son de gran valor simbólico como trasunto de otras tantas encrucijadas en la trayectoria de la España de la Restauración; especialmente el cambio de sensibilidad de los años noventa, orientado a la búsqueda de un conocimiento más profundo del alma humana y a una creciente atención a los pobres, a los enfermos y a los marginados, en sintonía con la orientación global del quehacer del Dr. Simarro., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Esta aportación se centra en uno de los aspectos centrales en los que Simarro participó: la incorporación del evolucionismo a la naciente y prometedora experimentadón biológica en nuestro país. Preocupado, primero, por la asimilación ideológica del mismo, desde su militancia activa en los círculos progresistas y liberales de Valencia y Madrid, pasando luego a la defensa pública del mismo dentro del naciente positivismo madrileño, junto con otros médicos y filósofos pioneros., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Temporal-order judgment (TOJ) and simultaneity judgment (SJ) tasks are used to study differences in speed of processing across sensory modalities, stimulus types, or experimental conditions. Matthews and Welch (2015) reported that observed performance in SJ and TOJ tasks is superior when visual stimuli are presented in the left visual field (LVF) compared to the right visual field (RVF), revealing an LVF advantage presumably reflecting attentional influences. Because observed performance reflects the interplay of perceptual and decisional processes involved in carrying out the tasks, analyses that separate out these influences are needed to determine the origin of the LVF advantage. We re-analyzed the data of Matthews and Welch (2015) using a model of performance in SJ and TOJ tasks that separates out these influences. Parameter estimates capturing the operation of perceptual processes did not differ between hemifields by these analyses, whereas parameter estimates capturing the operation of decisional processes differed. In line with other evidence, perceptual processing also did not differ between SJ and TOJ tasks. Thus, the LVF advantage occurs with identical speeds of processing in both visual hemifields. If attention is responsible for the LVF advantage, it does not exert its influence via prior entry., Ministerio de Economía y Competitividad (MINECO), Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Research on the perception of temporal order uses either temporal-order judgment (TOJ) tasks or synchrony judgment (SJ) tasks, in both of which two stimuli are presented with some temporal delay and observers must judge the order of presentation. Results generally differ across tasks, raising concerns about whether they measure the same processes. We present a model including sensory and decisional parameters that places these tasks in a common framework that allows studying their implications on observed performance. TOJ tasks imply specific decisional components that explain the discrepancy of results obtained with TOJ and SJ tasks. The model is also tested against published data on audiovisual temporal-order judgments, and the fit is satisfactory, although model parameters are more accurately estimated with SJ tasks. Measures of latent point of subjective simultaneity and latent sensitivity are defined that are invariant across tasks by isolating the sensory parameters governing observed performance, whereas decisional parameters vary across tasks and account for observed differences across them. Our analyses concur with other evidence advising against the use of TOJ tasks in research on perception of temporal order., Ministerio de Ciencia e Innovación (MICINN), Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

The transducer function mu for contrast perception describes the nonlinear mapping of stimulus contrast onto an internal response. Under a signal detection theory approach, the transducer model of contrast perception states that the internal response elicited by a stimulus of contrast c is a random variable with mean mu(c). Using this approach, we derive the formal relations between the transducer function, the threshold-versus-contrast (TvC) function, and the psychometric functions for contrast detection and discrimination in 2AFC tasks. We show that the mathematical form of the TvC function is determined only by mu, and that the psychometric functions for detection and discrimination have a common mathematical form with common parameters emanating from, and only from, the transducer function mu and the form of the distribution of the internal responses. We discuss the theoretical and practical implications of these relations, which have bearings on the tenability of certain mathematical forms for the psychometric function and on the suitability of empirical approaches to model validation. We also present the results of a comprehensive test of these relations using two alternative forms of the transducer model: a three-parameter version that renders logistic psychometric functions and a five-parameter version using Foley's variant of the Naka-Rushton equation as transducer function. Our results support the validity of the formal relations implied by the general transducer model, and the two versions that were contrasted account for our data equally well., Ministerio de Educación y Ciencia (España), Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Ulrich and Vorberg (2009) presented a method that fits distinct functions for each order of presentation of standard and test stimuli in a two-alternative forced-choice (2AFC) discrimination task, which removes the contaminating influence of order effects from estimates of the difference limen. The two functions are fitted simultaneously under the constraint that their average evaluates to 0.5 when test and standard have the same magnitude, which was regarded as a general property of 2AFC tasks. This constraint implies that physical identity produces indistinguishability, which is valid when test and standard are identical except for magnitude along the dimension of comparison. However, indistinguishability does not occur at physical identity when test and standard differ on dimensions other than that along which they are compared (e.g., vertical and horizontal lines of the same length are not perceived to have the same length). In these cases, the method of Ulrich and Vorberg cannot be used. We propose a generalization of their method for use in such cases and illustrate it with data from a 2AFC experiment involving length discrimination of horizontal and vertical lines. The resultant data could be fitted with our generalization but not with the method of Ulrich and Vorberg. Further extensions of this method are discussed., Ministerio de Ciencia e Innovación (MICINN), Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

We recently published an article (García-Pérez & Alcalá- Quintana, 2010) reanalyzing data presented by Lapid, Ulrich, and Rammsayer (2008) and discussing a theoretical argument developed by Ulrich and Vorberg (2009). The purpose of this note is to correct an error in our study that has some theoretical importance, although it does not affect the conclusion that was raised. The error lies in that asymptote parameters reflecting lapses or finger errors should not enter the constraint relating the psychometric functions that describe performance when the comparison stimulus in a two-alternative forced choice (2AFC) discrimination task is presented in the first or second interval., Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Morgan, Dillenburger, Raphael, and Solomon have shown that observers can use different response strategies when unsure of their answer, and, thus, they can voluntarily shift the location of the psychometric function estimated with the method of single stimuli (MSS; sometimes also referred to as the single-interval, two-alternative method). They wondered whether MSS could distinguish response bias from a true perceptual effect that would also shift the location of the psychometric function. We demonstrate theoretically that the inability to distinguish response bias from perceptual effects is an inherent shortcoming of MSS, although a three-response format including also an "undecided" response option may solve the problem under restrictive assumptions whose validity cannot be tested with MSS data. We also show that a proper two-alternative forced-choice (2AFC) task with the three-response format is free of all these problems so that bias and perceptual effects can easily be separated out. The use of a three-response 2AFC format is essential to eliminate a confound (response bias) in studies of perceptual effects and, hence, to eliminate a threat to the internal validity of research in this area., Ministerio de Ciencia e Innovación (MICINN), Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Because our eyes are set apart horizontally in our head, most disparities between the retinal images are horizontal. However, vertical disparities also occur, and can influence depth perception. The classic example is Ogle's induced effect (K. N. Ogle, 1938), in which applying a uniform vertical magnification to one eye's image produces the illusion that the surface has been rotated around a vertical axis. This is thought to be because uniform vertical magnifications can be produced in natural viewing when the eyes are in eccentric gaze (J. E. Mayhew, 1982; J. E. Mayhew & H. C. Longuet-Higgins, 1982). Thus, vertical magnification is taken by the visual system as indicating that the viewed surface is slanted away from the line of sight. Here, we demonstrate that the induced effect becomes stronger when the sign of the magnification alternates across the visual field. That is, as one moves horizontally across the screen, the left eye's image is alternately stretched and squashed vertically relative to the right eye's image, producing the illusion of a surface folded into triangular corrugations (H. Kaneko & I. P. Howard, 1997). For most subjects, slant judgments in this folded surface have lower thresholds and greater reliability than the classic induced effect, where magnification is applied uniformly across the whole visual field. This is remarkable, given that the disparity pattern of the classic induced effect can be produced by real surfaces with the eyes in eccentric gaze, whereas it is not clear that stripes of alternating vertical disparity could be produced by any physically realizable situation. The analogous improvement for alternating horizontal magnification is attributed to neuronal mechanisms which detect the jumps in horizontal disparity that occur at object boundaries. Our results suggest that a similar, previously unreported system may exist for vertical disparity. Jumps in vertical disparity do occur at object boundaries, and we suggest that our sur, Royal Society, Medical Research Council, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Our ability to discriminate motion direction in a Gabor patch diminishes with increasing size and contrast, indicating surround suppression. Discrimination is also impaired by a static low-spatial-frequency patch added to the moving stimulus, suggesting an antagonism between sensors tuned to fine and coarse features. Using Bayesian staircases, we measured duration thresholds in motion-direction discrimination tasks using vertically oriented Gabor patches moving at 2°/s. In two experiments, we tested two contrasts (2.8% and 46%), five window sizes (from 0.7° to 5°), and two spatial frequencies (1 c/deg and 3 c/deg), either presented alone or added to a static pattern. When the moving pattern was presented alone, duration thresholds increased with size at high contrast and decreased with size at low contrast. At low contrast, when a static pattern of 3 c/deg was added to a moving pattern of 1 c/deg, duration thresholds were similar to the case when the moving pattern was presented alone; however, at high contrast, duration thresholds were facilitated, eliminating the effect of surround suppression. When a static pattern of 1 c/deg was added to a moving pattern of 3 c/deg, duration thresholds increased about 4 times for high contrast and 2 times for low contrast. These results show that the antagonism between sensors tuned to fine and coarse scales is more complex than surround suppression, suggesting that it reflects the operation of a different mechanism., Ministerio de Economia y Competitividad (MINECO), Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Se repasan los momentos básicos de la historia de la Psicología Española en la que el Dr. Simarro ocupa un papel destacado. Continuador de la generación de los grandes fundadores, a la que en España perteneció F. Giner de los Ríos, Simarro aporta un nuevo impulso, como Cajal y Turró, a la Neuropsicología y a la Psicología. La generación siguiente es de consolidación y está representada por A. L. André. La tercera es la generación de los grandes renovadores, del inicio sistemático de la investigación experimental; destacan Lafora, Achúcarro y Sacristán, todos en alguna medida discípulos de Simarro y de Cajal. Discípulo de Lafora es Germain; con él y con sus coetáneos se consolida y amplía la investigación psicológica, con cierto predominio de las vertientes psiquiátrica y psicotécnica. Por ellos nos llega la Psicología de nuestro pasado y muy especialmente, los aspectos más estrictamente científicos de la línea que empieza en Giner y prosigue con Simarro, Lafora y Germain. Finalmente, Mariano Yela describe los fondos y recuerda el itinerario de la Fundación Simarro desde sus inicios hasta su depósito en la Facultad de Psicología, en los años 1982-1983., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

The perceived direction of motion of a brief visual stimulus that contains fine features reverses if static coarser features are added to it. Here we show that the reversal in perceived direction disappears if the stimulus is reduced in size from 2.8 deg to 0.35 deg radius. We show that for a stimulus with 1.4 deg radius, the reversals occur when the ratio between the contrast of the fine features and of the coarser features is higher than 0.8 and lower than 4. For stimulus with 0.35 deg radius, the reversals never appear for any contrast ratio. We also show that if the stimulus is presented within an annular window with small radius, errors disappear but they return if the radius is increased to 2 deg. The errors in motion discrimination described here can be explained by a model of motion sensing in which the signals from fine-scale and coarse-scale sensors are subtracted from one another (I. Serrano-Pedraza, P. Goddard, & A. M. Derrington, 2007). The model produces errors in direction when the signals in the fine and coarse sensors are approximately balanced. The errors disappear when stimulus size is reduced because the reduction in size differentially reduces the response of the low spatial frequency motion sensors., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Se repasan tres puntos centrales en la evolución de la Universidad Española en sus dos grandes etapas: la Universidad Antigua, que se extiende hasta las postrimerías del Antiguo Régimen, y la Universidad Liberal, que alcanza hasta los años de la Guerra Civil. De la consideración, primero,de la organización del poder y el gobierno académico, segundo, del método de enseñanza y, tercero, del profesorado, se infieren los argumentos que explican la tardía incorporación a la Universidad de un saber nuevo, con pretensiones experimentales, como era la Psicología representada por Simarro., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

The contrast detection threshold of a grating located in the periphery is increased if a surrounding grating of the same frequency and orientation is present. This inhibition between center and surround has been termed surround suppression. In this work we measured the spatial frequency bandwidth of surround suppression in the periphery for different spatial frequencies (0.5, 1.1, 3, and 5 cycles/deg) of a sinusoidal grating (target) surrounded by a grating with different spatial frequencies (surround). Using a Bayesian adaptive staircase, we measured contrast detection thresholds in an 8AFC detection task in which the target (grating with a 2.3-deg Butterworth window) could appear in one of eight possible positions at 4° eccentricity. The target was surrounded by a grating (with a 18° Butterworth window) with the same or an orthogonal orientation. In each session we fixed the spatial frequency of the target and changed the spatial frequency and the orientation of the surround. When the surround was orthogonal to the target, the thresholds were similar to those obtained without surround, independent of the surrounding spatial frequency. However, when the target and surround had the same orientation and spatial frequency, the contrast threshold was increased by a factor ranging from 3 to 6 across subjects. This suppression reduced rapidly as the spatial frequency of the surround moved away from that of the target. The bandwidth of the suppressive effect depended on spatial frequency, declining from 2.9 octaves at 0.5 c/deg to 1 octave for frequencies above 3 c/deg. This is consistent with the bandwidth of individual simple cells in visual cortex and of spatial frequency channels measured psychophysically, both of which decline with increasing spatial frequency. This suggests that surround suppression may be due to relatively precise inhibition by cells with the same tuning as the target., Ministerio de Ciencia e Innovación (MICINN), Royal Society, Medical Research Council, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

At high contrast, duration thresholds for motion direction discrimination deteriorate with increasing stimulus size. This counterintuitive result has been explained by the center-surround antagonism present in the neurons of visual area MT. Conversely, at very low contrast, direction discrimination improves with increasing size, a result that has been explained by spatial summation. In this investigation, we study the effects of stimulus shape and contrast on center-surround antagonism. Using adaptive Bayesian staircases, we measured duration thresholds of 5 subjects for vertically oriented Gabor patches of 1 cycle/deg with two types of oval Gaussian windows, one vertically elongated (Sx = 0.35, Sy = 2.5 deg) and other horizontally elongated (Sx = 2.5, Sy = 0.35 deg) moving rightward or leftward at a speed of 2 deg/s. We found that at high contrast (92%) duration thresholds were lower for vertically than horizontally elongated windows. However, at low contrast (2.8%), we found that duration thresholds were lower for horizontally than vertically elongated windows. These asymmetric results mirror the spatial non-homogeneity of the antagonistic surround found in MT neurons and suggest that the underlying center-surround antagonism is stronger along the direction of motion., Royal Society, Medical Research Council, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

We conducted two bi-national experiments regarding emotional and behavioral responses to a terrorist plot against commercial flights, examining both feelings and projected action. The studies employed hypothetical scenarios in which terrorists attacked airplanes with shoulder-fired missiles as they were landing or taking off from an international airport. The scenarios were built around two factorially crossed manipulated variables, each with three levels: (1) government announcements or actions (2) social norm, expressed as variation in airline ticket sales. Each respondent read a questionnaire containing only one of the nine scenarios. Experiment 1 was conducted in Spain and California (n = 360, 50% female), Experiment 2 in Israel and California (n = 504, 50% female). In both studies, fear and flight plans were not differentially affected by governmental response or social norm. Women expressed more fear than men. Experiment 1 examined the purpose of the trip. Most respondents would not change a planned flight to attend a close friend’s wedding or important job interview, but a substantial number would postpone a vacation or drive to a different location. Experiment 2 featured escalating attacks. These yielded increased fear and more canceled trips. Within both studies, responses were similar across countries despite national differences in direct experience with terrorism., Se realizaron dos experimentos bi-nacionales con respecto a las respuestas emocionales y conductuales a un plan terrorista contra vuelos comerciales, examinando ambas cosas: sentimientos y proyectos de acción. Los estudios emplearon escenarios hipotéticos en los que los terroristas atacaron los aviones con misiles disparados desde el hombro, ya que estaban aterrizando o despegando desde un aeropuerto internacional. Los escenarios fueron construidos alrededor de dos variables factoriales cruzadas, cada uno con tres niveles: (1) los anuncios o acciones del gobierno (2) norma social, expresada como la variación en la venta de billetes de avión. Cada encuestado leyó un cuestionario que contenía sólo uno de los nueve escenarios. El experimento 1 se realizó en España y California (n = 360, 50% mujeres), el experimento 2 en Israel y California (n = 504, 50% mujeres). En ambos estudios, el miedo y los planes de vuelo no fueron diferencialmente afectados por la respuesta gubernamental o la norma social. Las mujeres expresaron más miedo que los hombres. El experimento 1 examinó el propósito del viaje. La mayoría de los encuestados no cambiarían un vuelo planeado para asistir a la boda de un amigo cercano o para una importante entrevista de trabajo, pero un número considerable de participantes podrían posponer unas vacaciones o ir en coche a un lugar diferente. El experimento 2 contó con la escalada de los ataques. Estas aumentaron el temor y la cantidad de viajes cancelados. En ambos estudios, las respuestas fueron similares en todos los países a pesar de las diferencias nacionales y la experiencia directa con el terrorismo., Depto. de Economía Aplicada, Estructura e Historia, Fac. de Ciencias Económicas y Empresariales, TRUE, pub

Independent-channels models of perception of temporal order (also referred to as threshold models or perceptual latency models) have been ruled out because two formal properties of these models (monotonicity and parallelism) are not borne out by data from ternary tasks in which observers must judge whether stimulus A was presented before, after, or simultaneously with stimulus B. These models generally assume that observed responses are authentic indicators of unobservable judgments, but blinks, lapses of attention, or errors in pressing the response keys (maybe, but not only, motivated by time pressure when reaction times are being recorded) may make observers misreport their judgments or simply guess a response. We present an extension of independent-channels models that considers response errors and we show that the model produces psychometric functions that do not satisfy monotonicity and parallelism. The model is illustrated by fitting it to data from a published study in which the ternary task was used. The fitted functions describe very accurately the absence of monotonicity and parallelism shown by the data. These characteristics of empirical data are thus consistent with independent-channels models when response errors are taken into consideration. The implications of these results for the analysis and interpretation of temporal order judgment data are discussed., Ministerio de Ciencia e Innovación, Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub

Fixed-step-size (FSS) and Bayesian staircases are widely used methods to estimate sensory thresholds in 2AFC tasks, although a direct comparison of both types of procedure under identical conditions has not previously been reported. A simulation study and an empirical test were conducted to compare the performance of optimized Bayesian staircases with that of four optimized variants of FSS staircase differing as to up-down rule. The ultimate goal was to determine whether FSS or Bayesian staircases are the best choice in experimental psychophysics. The comparison considered the properties of the estimates (i.e. bias and standard errors) in relation to their cost (i.e. the number of trials to completion). The simulation study showed that mean estimates of Bayesian and FSS staircases are dependable when sufficient trials are given and that, in both cases, the standard deviation (SD) of the estimates decreases with number of trials, although the SD of Bayesian estimates is always lower than that of FSS estimates (and thus, Bayesian staircases are more efficient). The empirical test did not support these conclusions, as (1) neither procedure rendered estimates converging on some value, (2) standard deviations did not follow the expected pattern of decrease with number of trials, and (3) both procedures appeared to be equally efficient. Potential factors explaining the discrepancies between simulation and empirical results are commented upon and, all things considered, a sensible recommendation is for psychophysicists to run no fewer than 18 and no more than 30 reversals of an FSS staircase implementing the 1-up/3-down rule., Ministerio de Educación, Cultura y Deporte, Ministerio de Ciencia y Tecnología, Depto. de Psicobiología y Metodología en Ciencias del Comportamiento, Fac. de Psicología, TRUE, pub