How checking breeds doubt: Reduced performance in a simple workingmemory task

A paradox of memory research is that repeated checking results in a decrease in memory certainty, memory vividness and confidence [van den Hout, M. A., & Kindt, M. (2003a). Phenomenological validity of an OCD-memory model and the remember/know distinction. Behaviour Research and Therapy, 41, 369-378; van den Hout, M. A., & Kindt, M. (2003b). Repeated checking causes memory distrust. Behaviour Research and Therapy, 41, 301-316]. Although these findings have been mainly attributed to changes in episodic long-term memory, it has been suggested [Shimamura, A. P. (2000). Toward a cognitive neuroscience of metacognition. Consciousness and Cognition, 9, 313-323] that representations in working memory could already suffer from detrimental checking. In two experiments we set out to test this hypothesis by employing a delayed-match-to-sample working memory task. Letters had to be remembered in their correct locations, a task that was designed to engage the episodic short-term buffer of working memory [Baddeley, A. D. (2000). The episodic buffer: a new component in working memory? Trends in Cognitive Sciences, 4, 417-423]. Of most importance, we introduced an intermediate distractor question that was prone to induce frustrating and unnecessary checking on trials where no correct answer was possible. Reaction times and confidence ratings on the actual memory test of these trials confirmed the success of this manipulation. Most importantly, high checkers [cf. VOCI; Thordarson, D. S., Radomsky, A. S., Rachman, S., Shafran, R, Sawchuk, C. N., & Hakstian, A. R. (2004). The Vancouver obsessional compulsive inventory (VOCI). Behaviour Research and Therapy, 42(11), 1289-1314] were less accurate than low checkers when frustrating checking was induced, especially if the experimental context actually emphasized the irrelevance of the misleading question. The clinical relevance of this result was substantiated by means of an extreme groups comparison across the two studies. The findings are discussed in the context of detrimental checking and lack of distractor inhibition as a way of weakening fragile bindings within the episodic short-term buffer of Baddeley's (2000) model. Clinical implications, limitations and future research are considered.     

Can Attention Deficit Hyperactivity Disorder and Fetal Alcohol Spectrum Disorder be differentiated by motor and balance deficits?

There is an ongoing debate regarding the diagnostic overlap between Attention Deficit Hyperactivity Disorder (ADHD) and Fetal Alcohol Spectrum Disorder (FASD). Differential diagnosis is important because of treatment implications. Children aged 7–10 years (47 ADHD, 30 FASD, 39 controls) participated. The Movement Assessment Battery for Children (M-ABC) and the Clinical Observations of Motor and Postural Skills (COMPS) were used. Force plate and electromyography data were collected during static balance and balance perturbation. On the M-ABC both children with ADHD and FASD had more motor problems than controls. The ADHD-Combined and the ADHD-Predominantly Inattentive subgroups were similarly affected in their fine motor skills. On the COMPS, the majority of children in both groups performed in the normal range, but for those children clinically affected, it was the children with ADHD who were more likely to be severely impaired. The children with ADHD were characterized by early onset latencies of the tibialis anterior muscles and increased amplitudes of the gastrocnemius muscles. Difficulty scaling muscle force reflecting medial cerebellar involvement may be the key problem in ADHD. Cerebellar involvement in the postural instability in FASD awaits further study.     

The effect of time pressure on risky choice behavior

Thirty six subjects chose individually between pairs of gambles under three time pressure conditions: High (8 seconds), Medium (16 seconds) and Low (32 seconds). The gambles in each pair were equated for expected value but differed in variance, amounts to win and lose and their respective probabilities. Information about each dimension could be obtained by the subject sequentially according to his preference.The results show that subjects are less risky under High as compared to Medium and Low time pressure, risk taking being measured by choices of gambles with lower variance or lower amounts to lose and win. Subjects tended to spend more time observing the negative dimensions (amount to lose and probability of losing), whereas under low time pressure they preffered observing their positive counterparts. Information preference was found to be related to choices.Filtration of information and acceleration of its processing appear to be the strategies of coping with time pressure.     

Associative competition in operant conditioning: blocking the response-reinforcer association

Naive rats were trained to leverpress with a 30-sec delay-of-reinforcement contingency from the start of training. In Experiment 1, the delay interval for different groups of subjects included a signal in the first 5 sec, a signal in the last 5 sec, or no signal at any time. Rats with the signal at the start of the delay interval learned most rapidly. Rats with the signal at the end of the delay failed to learn. In Experiment 2, a choice procedure was used, in which each of two levers was associated with its own 30-sec delay of reinforcement. The delay for one lever included a 5-sec signal at the end of the delay. The delay for the second lever had no signal in its 30-sec delay. Preference was in favor of the lever without the signal in the delay interval. The results demonstrate that the acquisition of new response can be blocked in a manner analogous to the blocking of Pavlovian conditioning.     

The occupation of funeral director: A research note on work orientations

Factor analysis of responses of funeral directors to work orientation items is interpreted first as specifying major orientational themes and second as to how well the theoretical value components of professionalism and a business orientation hold together empirically. The analysis revealed that the professionalism model as operationalized in this study has no single underlying dimension which would define this orientation. It is thus suggested that the meaning of professionalism be altered to refer only to involvement in the occupational structure and not include service and autonomy. The business orientation model, however, appears to be fairly well supported by the data.     

The Relation of Cognitive and Memorial Processes to Persuasion in a Simulated Jury Trial

Four experiments investigated the dependence of persuasion on cognitive factors. All experiments employed a court case for which 795 subjects acted as jury members, reading summaries of both the prosecution and defense's testimony. The amount of objective information on both sides of the case was varied. Persuasion was a position function of the number of prosecution arguments and the number of defense arguments. This finding was extended by obtaining measures of the subjects'cognitive reactions to the case as well as their opinions and by following both of these measures over time. Both analysis of variance and multiple regression techniques showed that subjects could have derived their opinions from their cognitions about the case. This relationship also held up over time. These results suggest the general form of an information-processing theory of persuasion. One prediction of this theory is for an asymptotic function relating objective information to persuasion. This prediction received empirical support.