Task preparation and stimulus-evoked competition

The authors investigated how task competition evoked by a stimulus that affords both a currently relevant and a temporarily irrelevant task is affected by invalid preparation, i.e., preparation for the irrelevant task. Although invalid preparation was associated with a general performance cost, effects of stimulus-cued task competition were not enhanced on invalidly prepared trials. This result suggests that either preparation activates representations different from the ones by which stimulus cuing is mediated or that stimulus processing is postponed until invalid preparation has been corrected. In addition, invalid preparation resulted in impaired performance of the respective task when it became relevant on a subsequent trial. This result is consistent with the idea that competition due to invalid preparation is countered by task-specific inhibition.     

The development of therapeutic alliance during psychological assessment: patient and therapist perspectives across treatment

We examined the impact of patient- and therapist-rated alliance developed during psychological assessment on the subsequent alliance measured early and late in formal psychotherapy. We hypothesized that a working alliance developed during psychological assessment conducted from a collaborative therapeutic model of assessment (TMA; Finn & Tonsager, 1992, 1997; Fischer, 1994) between the patient and therapist would carry into formal psychotherapy. We also hypothesized that alliance for those patients receiving a TMA would be significantly greater than patients receiving psychological testing as usual. To test this hypothesis, we administered the Combined Alliance Short Form-Patient Version (Hatcher & Barends, 1996) and the Combined Alliance Short Form-Therapist Version (Hatcher, 1999) to a sample of outpatients and their therapists at the end of the assessment feedback session, early, and late in psychotherapy. The hypotheses were supported as alliance scales rated at the assessment feedback session demonstrated positive and significant relationships with alliance throughout formal psychotherapy and in relation to a control group. The clinical utility and research implications of these findings are discussed.     

What does it mean that an issue is conceptual in nature?

McGrath (2005/this issue) argues that "the conceptual complexity [italics added] of the constructs psychologists choose to measure and the scales they use to measure them has played an important role in the failure to develop more accurate measurement systems" (p. 112). Although we agree with this, we argue, in this commentary, that McGrath has misdiagnosed the source of these difficulties and that this misdiagnosis originates with an unresolved articulation of the nature of a conceptual issue and of the relationship between conceptual and empirical issues in science.     

Lack of the metabotropic glutamate receptor subtype 7 selectively modulates Theta rhythm and working memory

Metabotropic glutamate receptors (mGluRs) are known to play a role in synaptic plasticity and learning. We have previously shown that mGluR7 deletion in mice produces a selective working memory (WM) impairment, while other types of memory such as reference memory remain unaffected. Since WM has been associated with Theta activity (6-12 Hz) in EEGs, and since EEG abnormalities have been observed in these mice before, we studied the effect of mGluR7 gene ablation on EEG activity in the hippocampus, in particular in the Theta range, during performance of a WM task. In an eight-arm maze with four arms baited, mGluR7 knock-out (KO) and wild-type mice committed the same number of reference memory errors, whereas KOs committed more WM errors. While performing the task, KO mice showed substantially higher Theta amplitudes, and the ratio of Theta to overall EEG power was much increased. No change was seen in the Delta (0-5 Hz), or Gamma (30-40 Hz) EEG bands compared with controls. When recording EEGs during periods of rest in the home cages, no difference was seen between groups. These findings suggest that mGluR7 is important for modulation and control of Theta activity. Since only WM was affected, and only the Theta range of EEG activity was altered, these results show a correlation between Theta rhythm and WM performance, and therefore support the concept that Theta activity in the hippocampus is involved in WM storage.     

Choice with initial and terminal link reinforcement: an alternative self-control paradigm

Self-control is demonstrated when a less desirable immediate outcome is chosen to ensure a substantially better future. In a novel animal analogue of this situation, primary reinforcement was delivered in both the initial and terminal links of a concurrent chain schedule. Rats made initial link choices between equal amounts of ethanol-free or ethanol-containing milk. Choosing the ethanol-free reinforcer resulted in delivery of the larger terminal link reinforcer and was thus analogous to self-control. Self-control decreased as the delay between initial and terminal links increased. The results have implications for human choice situations where decisions are made between two immediately available reinforcement alternatives each associated with a different delayed outcome.     

Effects of the presence of others on food intake: a normative interpretation

The authors review the effect of the presence of others on food intake. In social facilitation studies, people tend to eat more in groups than when alone. In modeling studies, the presence of others may facilitate or inhibit intake, depending on how much these other people eat. Studies of impression management demonstrate that people tend to eat less in the presence of others than when alone. The authors attempt to reconcile these divergent literatures by reference to a model of inhibitory norms that govern eating. In the presence of palatable food, and in the absence of clear signals of satiety, people look outward to cues from the environment to determine when to stop eating. Socially derived inhibitory norms can account for either increased or decreased intake in the presence of others, depending on how much the others eat and the extent to which one is eager to impress them.     

Speech errors, disfluencies, and self-repairs of stutterers in two accuracy conditions

The purpose of the present study was to see whether the covert repair hypothesis, which views normal disfluencies as the by-products of covert self-repairing of internal speech (programming) errors, applies to habitual stutterers. To this end, we examined the effects of emphasis on speech accuracy in stutterers on three sorts of incidents: speech errors, disfluencies (also including stuttering), and self-repairs. In a condition in which they performed a speech task under instructions stressing the accuracy of speaking, stutterers made considerably fewer speech errors, than in a condition in which speech accuracy could be ignored. On the other hand, disfluency and self-repair rates remained about the same. They did increase, however, relative to speech error rates with accuracy emphasis. A control group of normal speakers performed in a similar way. Apparently, disfluencies behaved like self-repairs. These results support the covert repair hypothesis of disfluency, both for stutterers and for normal speakers.     

When can attention not be divided?

Humans can guide simple concurrent and seemingly independent movements of digits between hands, but it is shown here that they find it impossible to do this with digits within a hand. This inability demonstrates a basic characteristic of the relation between attention and the control of the skeletal musculature. Mechanisms that are available to provide the illusion of concurrent and independent guidance of separate movements between hands are not available within a single-hand control system. There is no reason to believe that the inability to divide focal attention in the guidance of two concurrent controlled activities, as exemplified in the example of within-hand movements, does not also extend to nonmotor processes.