Extrafoveal Processing in Categorical Search for Geometric Shapes: General Tendencies and Individual Variations

The paper addresses the capabilities and limitations of extrafoveal processing during a categorical visual search. Previous research has established that a target could be identified from the very first or without any saccade, suggesting that extrafoveal perception is necessarily involved. However, the limits in complexity defining the processed information are still not clear. We performed four experiments with a gradual increase of stimuli complexity to determine the role of extrafoveal processing in searching for the categorically defined geometric shape. The series of experiments demonstrated a significant role of extrafoveal processing while searching for simple two-dimensional shapes and its gradual decrease in a condition with more complicated three-dimensional shapes. The factors of objects’ spatial orientation and distractor homogeneity significantly influenced both reaction time and the number of saccades required to identify a categorically defined target. An analysis of the individual p-value distributions revealed pronounced individual differences in using extrafoveal analysis and allowed examination of the performance of each particular participant. The condition with the forced prohibition of eye movements enabled us to investigate the efficacy of covert attention in the condition with complicated shapes. Our results indicate that both foveal and extrafoveal processing are simultaneously involved during a categorical search, and the specificity of their interaction is determined by the spatial orientation of objects, type of distractors, the prohibition to use overt attention, and individual characteristics of the participants.     

Excitotoxic lesions of the parafascicular nucleus produce deficits in a socially transmitted food preference

The parafascicular (PF) nucleus, a posterior component of the intralaminar nuclei of the thalamus, is considered to be an essential structure in the feedback circuits of basal ganglia-thalamo-cortical systems that critically participate in cognitive processes. To study the PF contribution to processing of behaviorally significant information during specific episodes of learning, we investigated the effects of damaging the PF nucleus in the acquisition of a natural form of social olfactory learning, the socially transmitted food preference (STFP) task. This task is a non-spatial paradigm that exhibits some of the characteristics of relational memory because it requires that animals use information obtained in one episode to guide later behavior in different circumstances. Adult male Wistar rats were submitted to pretraining bilateral N-methyl-D-aspartate (0.15 M, pH 7.4) lesions of the PF (0.4 microl/side, 0.2 microl/min). The behavioral effects of PF lesions were compared to vehicle- and sham-operated control groups and two retention delays were considered in separate groups: immediately (Lesion-I, Vehicle-I, and Sham-I groups) and 24h after training (Lesion-24, Vehicle-24, and Sham-24 groups). PF lesions produced delay-independent impairments in the STFP suggesting that this nucleus might modulate the acquisition of this odor-odor association task. Results are discussed in the context of medial prefrontal cortex deafferentation induced by PF damage.     

Acute treatment of inpatients with psychotic symptoms using Acceptance and Commitment Therapy: pilot results

Cognitive behavior therapy (CBT) has been demonstrated in a number of randomized controlled trials to be efficacious as an adjunctive treatment for psychotic disorders. Emerging evidence suggests the usefulness of CBT interventions that incorporate acceptance/mindfulness-based approaches for this population. The current study extended previous research by Bach and Hayes (2002. The use of Acceptance and Commitment Therapy to prevent the rehospitalization of psychotic patients: A randomized controlled trial. Journal of Consulting and Clinical Psychology, 70, 1129-1139) using Acceptance and Commitment Therapy (ACT) in the treatment of psychosis. Psychiatric inpatients with psychotic symptoms were randomly assigned to enhanced treatment as usual (ETAU) or ETAU plus individual sessions of ACT. At discharge from the hospital, results suggested short-term advantages in the ACT group in affective symptoms, overall improvement, social impairment, and distress associated with hallucinations. In addition, more participants in the ACT condition reached clinically significant symptom improvement at discharge. Although 4-month rehospitalization rates were lower in the ACT group, these differences did not reach statistical significance. Decreases in the believability of hallucinations during treatment were observed only in the ACT condition, and change in believability was strongly associated with change in distress after controlling for change in the frequency of hallucinations. Results are interpreted as largely consistent with the findings of Bach and Hayes and warrant further investigations with larger samples.     

Psychiatric patient and informant reports of patient behavior

Informant reports of psychiatric patient behavior are collected routinely during intake interviews and to monitor therapeutic interventions. We investigated agreement between informant and adult psychiatric patient reports of patient behaviors (N=110). Behaviors were about substance use, physical and mental health, employment, illegal behavior, and recreational and social activities. Informant agreement with patients regarding whether or not a particular behavior occurred recently and also behavior frequency ratings were moderate overall (M r=.47 for frequency) and highly variable (rs=-.09 to .80). No informant, patient, or relationship characteristics were found consistently to moderate agreement. Thus, informants can report very accurately about the presence and frequency of some, but not all, patient behaviors. Low patient-informant agreement may be due to informants having relatively less detailed knowledge of patient behavior over time or patients not reporting accurately about certain behaviors.     

Social tuning of automatic racial attitudes: the role of affiliative motivation

Consistent with the affiliative social tuning hypothesis, this study showed that the desire to get along with another person shifted participants' automatic attitudes toward the ostensible attitudes of that person. In Experiment 1, the automatic racial attitudes of women but not men emulated those of an experimenter displaying race-egalitarian attitudes or attitudes neutral with respect to race. Mediational analysis revealed that the gender difference in social tuning was mediated by liking for the experimenter. In Experiment 2, the likability of the experimenter was manipulated. Individuals who interacted with a likable experimenter exhibited social tuning more so than did those who interacted with a rude experimenter. These findings suggest that affiliative motives may elicit malleability of automatic attitudes independent of manipulations of social group exemplars.     

Comment on short-term variation in subjective sleepiness

Subjective sleepiness at different times is often measured in studies on sleep loss, night work, or drug effects. However, the context at the time of rating may influence results. The present study examined sleepiness throughout the day at hourly intervals and during controlled activities [reading, writing, walking, social interaction (discussion), etc.] by 10-min. intervals for 3 hr. This was done on a normal working day preceded by a scheduled early rising (to invite sleepiness) for six subjects. Analysis showed a significant U-shaped pattern across the day with peaks in the early morning and late evening. A walk and social interaction were associated with low sleepiness, compared to sedentary and quiet office work. None of this was visible in the hourly ratings. There was also a pronounced afternoon increase in sleepiness, that was not observable with hourly ratings. It was concluded that there are large variations in sleepiness related to time of day and also to context and that sparse sampling of subjective sleepiness may miss much of this variation.     

Conceptual information on objects' locations

According to traditional views, basic and subordinate concepts elicit perceptual information, superordinate concepts abstract information. Two experiments showed that also superordinate concepts activate perceptual and contextual information. In Experiment 1 participants evaluated the adequacy of Scene- and Object-like locations ascribed to basic and superordinate concepts. Superordinate concepts were judged faster when paired with Scene-like locations, where many exemplars can coexist, than with Object-like locations. The results were replicated and extended in the second experiment with a location production task. Theoretical accounts for the results are discussed.