Effects of level of arousal and type of task on bilateral skin conductance asymmetry and conjugate lateral eye movements

Several recent studies have indicated that the degree and direction of bilateral skin conductance (BSC) asymmetry and the direction of conjugate lateral eye movements (CLEMs) both index hemispheric functioning. Evidence also suggests that BSC asymmetry decreases and CLEMs become more unidirectional as level of arousal increases. Thirty-two normal adults received an habituation series of five-second tones followed by 40 questions. All stimuli were tape recorded. The questions (Schwartz, Davidson, and Maer, 1975) were grouped in four series: 10 verbal-emotional, 10 verbalnonemotional, 10 spatial-emotional, and 10 spatial-nonemotional. The order in which the four series were presented was counterbalanced across subjects. Prior to each question, subjects fixated the face of a mannequin. Sixteen subjects (high arousal) had five seconds to contemplate their answer; the remaining 16 (low arousal) had 10 seconds. Instructions for the high arousal group specified that intelligence and problem-solving ability was being tested, and that speed and accuracy were very important. Those for the low arousal group indicated casually that subjects were to ponder a series of questions. BSC levels, SC response amplitudes, and CLEMs were measured during a five-second interval following each tone or question. BSC levels were greater under the High Arousal condition. While approximately two-thirds of the subjects showed BSC asymmetry (roughly evenly divided between those with larger left and right hand responses), neither the degree nor direction of the asymmetries changed as a function of question type. While CLEM direction was more sensitive to question type under low arousal, (i.e., verbal questions resulted in predominantly right-going CLEMs and spatial questions resulted in predominantly left-going CLEMs) they tended to be stereotyped (i.e., unidirectional) under high arousal. Finally, no relationship was observed between CLEM direction and BSC asymmetry under either high or low arousal condition.     

The development of sensitivity to biological motion in noise

We investigated developmental changes in sensitivity to biological motion by asking 6-year-olds, 9-year-olds, and adults (twenty-four in each group) to discriminate point-light biological motion displays depicting one of a variety of human movements from scrambled versions of the same displays. When tested without noise dots, participants at all ages performed near ceiling levels and no differences in accuracy were found among the three age groups. Age differences emerged in the second task, in which we used a staircase procedure to determine threshold values of the number of noise dots that could be tolerated in producing a percentage correct value corresponding to a d' value of 1.4. Sensitivity to biological motion improved linearly with age (p < 0.01), with 6-year-olds performing significantly more poorly than adults. This immature performance contrasts with adult-like accuracy by 4 years of age for sensitivity to global motion (Parrish et al, 2005 Vision Research 45 827-837). The comparison implies an immaturity at 6 years of age in the neural networks involved specifically in the processing of biological motion, networks that may include the superior temporal sulcus (STS).     

The evolutionary significance of depressive symptoms: different adverse situations lead to different depressive symptom patterns

Although much depression may be dysfunctional, the capacity to experience normal depressive symptoms in response to certain adverse situations appears to have been shaped by natural selection. If this is true, then different kinds of situations may evoke different patterns of depressive symptoms that are well suited to solving the adaptive challenges specific to each situation. The authors called this the situation-symptom congruence hypothesis. They tested this hypothesis by asking 445 participants to identify depressive symptoms that followed a recent adverse situation. Guilt, rumination, fatigue, and pessimism were prominent following failed efforts; crying, sadness, and desire for social support were prominent following social losses. These significant differences were replicated in an experiment in which 113 students were randomly assigned to visualize a major failure or the death of a loved one.     

Rapid acquisition in concurrent chains: evidence for a decision model

Pigeons' choice in concurrent chains can adapt to rapidly changing contingencies. Grace, Bragason, and McLean (2003) found that relative initial-link response rate was sensitive to the immediacy ratio in the current session when one of the terminal-link fixed-interval schedules was changed daily according to a pseudorandom binary sequence (e.g., Schofield & Davison, 1997). The present experiment tested whether the degree of variation in delays across sessions had any effect on acquisition rate in Grace et al.'s (2003) rapid-acquisition procedure. In one condition ("minimal variation"), the left terminal link was always fixed-interval 8 s and the right terminal link was either fixed-interval 4 s or fixed-interval 16 s. In the other condition ("maximal variation"), a unique pair of fixed-interval values was used in each session. Responding was sensitive to the current-session immediacy ratio in both conditions, but across subjects there was no systematic difference in sensitivity. These results challenge the view that initial-link responding in the rapid-acquisition procedure is determined by changes in the learned value of the terminal-link stimuli, and suggests instead that a process resembling categorical discrimination may control performance. A decision model based on the assumption that delays are categorized as short or long relative to the history of delays provided a good account of the data and shows promise in being able to explain other choice phenomena.     

Visual form recognition threshold and the psychological refractory period

Two experiments studied the effect of a reaction time response (RT) on visual form recognition threshold when the temporal interval separating the RT stimulus and the recognition stimulus was short. In Experiment 1 an initial RT response to an auditory signal did not impair the subsequent forced-choice visual form recognition threshold. Interstimulus intervals (ISI) of 0, 50, 100, 150, and 200 msec were used; S was always aware of the ISI under test. In Experiment 2 a visual stimulus was used to elicit the R T response; this shift to an intramodal stimulus did not alter the recognition threshold. These data were interpreted as supporting the hypothesis that two stimulus events can be processed simultaneously even when the temporal interval between them is short.     

I didn't think of that

Consider cases in which an agent simply doesn.t think to do a certain thing, or doesn't think of a crucial consideration favoring doing a certain thing, or intends to do a certain thing but forgets to do it. In such a case, is the agent able to do the thing that she fails to do? Assume that commonly we all-in can do things that we do not do. Here I argue that, given this assumption, in the cases under consideration, too, commonly agents all-in can do the things they fail to do.     

“It takes a village to heal a child”: Necessary spectrum of expertise and benevolence by therapists,Non-Governmental Organizations,and the United Nations in managing war-zone stress in children traumatized by political violence

This article highlights the post-traumatic stress responses in some war-zone children who were exposed to political violence—witnessing unspeakable horror, maimings, brutal beatings, torture, and murders. Children inducted into rebel military units to serve as child-soldiers further traumatized self and others by raping and killing children and adults. Additionally, some children go without food, shelter, and adult protection, while finding themselves as refugees in a foreign country. This article advances some conceptual, technical, and practical issues in intervention with these children and provides a model of intervention that seeks to integrate established international policies of the United Nations (UN) and Non-Governmental Organizations (NGOs) along with cognitive, behavioral, and psychodynamic clinical approaches in the context of cultural/racial sensitivity and indigenous folk medicine. The child's adaptational strengths are discussed, and the recognition and management of transference and countertransference are not ignored in the treatment of traumatized children. Basically, the author's point of view is that Western models of interventions are very useful, but that the personal, cultural, social, spiritual, and economic resources of the child's homeland or village probably constitute the best system for healing and integration after brief or continuous exposure to political violence.