The influence of task characteristics on younger and older adult motor overflow

This study investigated the influence of attentional and motor demands on motor overflow in 17 healthy young (18-35 years) and 17 older adults (60-80 years). Participants performed a finger pressing task by exerting either 33% or 66% of their maximal force output using their dominant or nondominant hand. Overflow was concurrently recorded in the passive hand. Attention was manipulated via a tactile stimulus presented to one or both hands for certain trials. Results showed that older adults exhibited greater overflow than young adults and that the effect of target force was exacerbated in older adults. Further, only older adult overflow was increased when tactile stimulation was directed to one or both hands. Increased overflow in older adults may result from bilateral cortical activation that is influenced by increased task demands. To perform comparatively to younger adults, older adults may compensate for age-related brain changes by recruiting an increased cortical network.     

Contributions of volumetrics of the hippocampus and thalamus to verbal memory in temporal lobe epilepsy patients

Recent theories have posited that the hippocampus and thalamus serve distinct, yet related, roles in episodic memory. Whereas the hippocampus has been implicated in long-term memory encoding and storage, the thalamus, as a whole, has been implicated in the selection of items for subsequent encoding and the use of retrieval strategies. However, dissociating the memory impairment that occurs following thalamic injury as distinguished from that following hippocampal injury has proven difficult. This study examined relationships between MRI volumetric measures of the hippocampus and thalamus and their contributions to prose and rote verbal memory functioning in 18 patients with intractable temporal lobe epilepsy (TLE). Results revealed that bilateral hippocampal and thalamic volume independently predicted delayed prose verbal memory functioning. However, bilateral hippocampal, but not thalamic, volume predicted delayed rote verbal memory functioning. Follow-up analyses indicated that bilateral thalamic volume independently predicted immediate prose, but not immediate rote, verbal recall, whereas bilateral hippocampal volume was not associated with any of these immediate memory measures. These findings underscore the cognitive significance of thalamic atrophy in chronic TLE, demonstrating that hippocampal and thalamic volume make quantitatively, and perhaps qualitatively, distinct contributions to episodic memory functioning in TLE patients. They are also consistent with theories proposing that the hippocampus supports long-term memory encoding and storage, whereas the thalamus is implicated in the executive aspects of episodic memory.     

Consciousness of targets during the attentional blink: a gradual or all-or-none dimension?

Models of consciousness differ in whether they predict a gradual change or a discontinuous transition between nonconscious and conscious perception. Sergent and Dehaene (Psychological Science, 15, 720-728, 2004) asked subjects to rate on a continuous scale the subjective visibility of target words presented during an attentional blink. They found that these words were either detected as well as targets outside the attentional-blink period or not detected at all, and interpreted these results as support for a discontinuous transition between nonconscious and conscious processing. We present results from 4 attentional-blink experiments showing that this all-or-none rating pattern disappears with the use of an alternative measure of consciousness (post-decision wagering) and a more difficult identification task. Instead, under these circumstances, subjects used the consciousness rating scales in a continuous fashion. These results are more consistent with models that assume a gradual change between nonconscious and conscious perception during the attentional blink.     

Multiple Deescalating Requests,Statistical Information,and Compliance: A Field Experiment1

Although prior research on influence has identified numerous techniques for increasing donation rates (see e. g., Cialdini, 1988), the problem of increasing donation sizes has been neglected. We conducted a field experiment in a telemarketing fundraising context to examine the effectiveness of three influence techniques for increasing the size of donations. The results indicate that the multiple-deescalating-requests technique was effective for increasing donation sizes. However, statistical information-based techniques were ineffective. Theoretical and applied implications of the results are discussed.     

The effects of skill demands and object position on the distribution of preferred hand reaches

Performance-based measures of hand preference have been developed as an objective method of examining handedness. Previous research using this method showed that both skill demands and the position of the object in working space affect preferential hand reaching. Specifically, preferred hand reaches predominated in left hemispace, in spite of the biomechanical inefficiency involved in reaching across the body midline. This was mediated by the skill demands, with a higher frequency of preferred hand reaches for tasks requiring more skill. To further examine this issue, we increased the task skill demands. Twenty-two right-handed adults reached for five tools located in an array of five positions in front of them. Participants were required to pick up the tool, pick up and demonstrate how to use it, or pick up and actually use the tool on the materials provided. The results showed that the frequency of right hand reaches was greatest for the tool use condition. This effect was mediated by the position of the object in hemispace, with more right hand reaches occurring for the Use task in left hemispace than the other tasks, in support of our previous work.     

Evidence of construct validity of the interest scales on the Campbell Interest and Skill Survey

This study explored evidence of the construct validity of the interest scales on the Campbell Interest and Skill Survey (CISS; Campbell, Hyne, & Nilsen, 1992) by testing evidence for convergent validity with the Strong Interest Inventory (SII; Hansen & Campbell, 1985). Two hypotheses were formulated. First, matching CISS and SII scales were expected to be more positively correlated compared to non-matching scales. Second, Holland's hexagonal calculus assumption (Holland, 1973) was expected to emerge in the pattern of intercorrelations among CISS and SII scales. These hypotheses were tested using correlational and factor analyses. Results supported the hypotheses and demonstrated evidence of good convergent and construct validity for scores on the CISS interest scales. Implications for the use of the CISS in counseling and for research on Holland's theory are discussed, and directions for future research are presented.     

How does clients' method of payment influence psychologists' diagnostic decisions?

To what extent does payment method (managed care vs. out of pocket) influence the likelihood that an independent practitioner will assign a Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994) diagnosis to a client? When a practitioner does diagnose, how does payment method influence the specific choice of a diagnostic category? Independent practitioners responded to a vignette describing a fictitious client with symptoms of depression or anxiety. In half of the vignettes, the fictitious client intended to pay via managed care; in the other half, the fictitious client intended to pay out of pocket. Payment method had a very significant impact on diagnosis such that relative to out-of-pocket clients, managed care clients were much more likely to receive diagnoses and more likely to receive adjustment disorder diagnoses in particular. We discuss implications involving informed consent and other ethical issues.