Search

Background: Psychopathy is a severe personality disorder that has been linked to impaired behavioural adaptation during reinforcement learning. Recent electrophysiological studies have suggested that psychopathy is related to impairments in intentionally using information relevant for adapting behaviour, whereas these impairments remain absent for behaviour relying on automatic use of information. We sought to investigate whether previously found impairments in response reversal in individuals with psychopathy also follow this dichotomy. We expected response reversal to be intact when the automatic use of information was facilitated. In contrast, we expected impaired response reversal when intentional use of information was required. Methods: We included offenders with psychopathy and matched healthy controls in 2 experiments with a probabilistic cued go/no-go reaction time task. The task implicated the learning and reversal of 2 predictive contingencies. In experiment 1, participants were not informed about the inclusion of a learning component, thus making cue-dependent learning automatic/incidental. In experiment 2, the instructions required participants to actively monitor and learn predictive relationships, giving learning a controlled/intentional nature. Results: While there were no significant group differences in acquisition learning in either experiment, the results revealed impaired response reversal in offenders with psychopathy when controlled learning was facilitated. Interestingly, this impairment was absent when automatic learning was predominant. Limitations: Possible limitations are the use of a nonforensic control group and of self-report measures for drug use. Conclusion: Response reversal deficits in individuals with psychopathy are modulated by the context provided by the instructions, according to the distinction between automatic and controlled processing in these individuals., Introduction Our ability to learn associations between events with rewarding or punishing outcomes plays an important role in guiding our behaviour. (1) Of equal importance is our capacity to successfully [...]

Classically, neurons communicate by anterograde conduction of action potentials. However, information can also pass backward along axons, a process that is essential during the development of the nervous system. Here we propose a role for such 'retroaxonal' signals in adult learning. We hypothesize that strengthening of a neuron's output synapses stabilizes recent changes in the same neuron's inputs. During learning, the input synapses of many neurons undergo transient changes, resulting in altered spiking activity. If this in turn promotes strengthening of output synapses, the recent synaptic changes will be stabilized; otherwise they will decay. A representation of sensory stimuli therefore evolves that is tailored to the demands of behavioral tasks. We describe a candidate molecular mechanism for this process involving the activation of CREB by retrograde neurotrophin signals.

Although prior research clearly shows that toddlers have difficulty learning from video, the basis for their difficulty is unknown. In the 2 current experiments, the effect of social feedback on 2-year-olds' use of information from video was assessed. Children who were told 'face to face' where to find a hidden toy typically found it, but children who were given the same information by a person on video did not. Children who engaged in a 5-min contingent interaction with a person (including social cues and personal references) through closed-circuit video before the hiding task used information provided to find the toy. These findings have important implications for educational television and use of video stimuli in laboratory-based research with young children.

Summation tests were used to assess whether participants in a human predictive judgement task learned that some cues (foods) prevented the occurrence of the outcome (migraine). In three experiments the preventative effect of a conditioned inhibitor, I, trained in the design, P+, PI-, I-, was stronger than that of a negative control cue, N, that had been presented alone with the same frequency and simply predicted no outcome. This control cue, N, also passed the summation test when compared to a novel control cue. Experiments 2 and 3 examined whether the latter negative control effect was attributable to differential inhibition. Manipulations designed to alter context learning and the magnitude of the negative contingency did not affect the properties of the negative control cue. Thus, these experiments did not support the possibility that a cue given simple negative training acquires differential inhibition. Regardless of the mechanism underlying the negative control effect, the consistent finding that the conditioned inhibition cue, I, reduced prediction of the outcome more than did the negative control cue, N, provides evidence for true conditioned inhibition whose acquisition requires co-occurrence of the preventative cue with a positive training cue.

The influence of a secondary task on forward blocking of human contingency ratings was examined. A smaller blocking effect was found when participants performed a highly demanding secondary task than when they performed a less demanding secondary task. The modulatory effect of secondary task difficulty was significant only when the secondary task was administered during both the learning and the test phase of the contingency judgement task. The results suggest that forward blocking in human contingency learning cannot be fully accounted for by associative processes. Instead, forward blocking seems to depend at least partially on deliberate deductive reasoning processes.

Previous research has shown that men and boys learn routes faster and with fewer errors than do women and girls. Research with adults suggests that men use Euclidean cues when learning a route, whereas women use landmark-based strategies. The strategies used by children have received little study. In Exp. 1, 50 boys and girls, ages 5 to 12 years, were shown a map that contained only landmarks (no streets or roads) and were asked to learn a route consisting of 23 of the landmarks. The children used a pointer to trace the route on the map to a criterion of two successive trials without errors. The performance of boys and girls did not differ significantly on this route-learning task on three measures (number of trials to reach criterion, total time to reach criterion, and total number of errors). In Exp. 2, 52 boys and girls, ages 5 to 12 years, were shown the same map as in Exp. 1 and were asked to learn a route consisting of 12 landmarks. The children traced the route by picking pictures of landmarks in the correct order from a stack of cards with pictures of landmarks on them. Girls made significantly fewer errors than boys on this route-learning task in Exp. 2, and a significantly larger number of girls than boys completed the task. None of the boys in the 5- to 6-yr.-old age group learned the route. When Euclidean cues were minimized in Exp. 2, boys made more errors and took as much time as girls to reach the criterion of two successive correct trials.

The main purpose was to investigate how we process pictograms and to examine the effects of learning on visual field differences when participants over-learn the meaning of each pictogram. 15 students were required to judge whether the referent of each symbol was either larger or smaller than the referent of the standard stimulus (Test 1). Several days later the same task was conducted (Test 2). Although a right visual field advantage was observed in Test 1, it was not apparent at Test 2 after participants had studied the pictogram list repeatedly. These results suggest that pictograms might be processed in much the same way as other ordinary verbal stimuli at a very early stage of learning. Participants could, however, comprehend the pictograms by employing a kind of imagery processing after they were familiar with the symbols.

The main purpose of most educational and training programs is that the person will acquire some specified knowledge, retain it until a later time when it will be retrieved and employed to make decisions, select and execute actions, etc. Previous research has indicated that there might be a positive relation between an individual's certainty about the correctness of learned responses and how well the material is retained over shorter time-periods. In the present study, 39 men and 38 women learned the names of eight different hand pliers; they were also assessing their certainty about the names of the pliers. After the learning session, the participants returned after either 1, 6, or 12 wk. for a retention and relearning session. Analysis showed that higher certainty was associated positively with retention. The men were more prone than the women to rate themselves as being 'Extremely sure' of being correct, even when they, in fact, were wrong. Also, men and women learned the material equally fast, but the men required significantly fewer trials than the women to relearn the material. Inclusion of ratings of certainty offers a convenient way of assessing when training has been sufficient and facilitates detection of misinformation (sure-but-wrong answers).

Using a serial reaction-time task, the implicit memory performances of 29 high scoring (schizotypes) and 24 low scoring subjects (controls) on the German version of the 1997 Schizotypal Personality Questionnaire by Klein, Andresen, and Jahn were compared. To test the hypothesis that schizotypes show a differential deficit, subjects participated either in a single task condition of the serial reaction-time task or in a dual task condition of a secondary tone-counting task. Neither under single task conditions nor under dual task conditions did schizotypes show any impairment of implicit memory compared with controls. In addition, a separate analysis of the response latencies for the unique and ambiguous transitions of the repeated sequence did not indicate any differences between the two groups. These findings support and augment the results reported by Ferraro and Okerlund (1995).