Strong items get suppressed, weak items do not: The role of item strength in output interference

An experiment is reported that examines the role of item strength in output interference. Subjects studied two types of categorized item lists: lists in which each category consisted of strong and moderate items, and lists in which each category consisted of weak and moderate items. Different degrees of item strength were accomplished by varying the items’ taxonomic frequency within a category. The subjects either recalled a category’s strong and weak items before its moderate items, or vice versa. The prior recall of the moderate items impaired the later recall of the strong items, but did not impair the later recall of the weak items. This effect of item strength indicates that output interference is caused by a process of retrieval suppression. It additionally suggests that, in order to minimize output-interference effects in recall, a list’s strong items should be recalled before its weak items.     

Disinhibition of return: Unnecessary and unlikely

Recently, from data obtained with a temporal order judgment (TOJ) task, Gibson and Egeth (1994) concluded that inhibition of return (IOR; a response time effect that reveals slower responding to targets at previously cued versus uncued locations) reflects impaired perceptual processing. By replotting their data, we demonstrate that the perception of temporal order is influenced only by the facilitatory effect of a cue at short stimulus onset asynchronies (SOAs) and is unaffected by IOR at long SO As. The target paper proposed that, when extra stimuli are presented at task-relevant locations (i.e., in the TOJ task), IOR is prevented by a hypothetical process that is known as disinhibition of return (DOR). We argue that the assumptions that IOR affects perceptual processing and that DOR exists are unnecessary, as a more parsimonious response-based interpretation of IOR is consistent with their data. Further, we summarize recent results and present new data that demonstrate that DOR is unlikely.     

Role of the striatum and the cerebellum in motor skill acquisition

Motor skill acquisition was investigated in patients with Parkinson's disease (PD) or cerebellar dysfunction using two sensory-guided tracking tasks. The subjects had to learn to track a visual target (a square) on a computer screen by moving a joystick under two different conditions. In the unreversed task, the horizontal target movements were semi-predictable and could be anticipated. In the reversed task, the horizontal movements of a pointer which had to be kept within the target square were mirror-reversed to the joystick movements. PD patients showed intact learning of the semi-predictable task and reduced learning of the mirror-reversed task; patients with cerebellar dysfunction showed the opposite pattern. These findings are discussed in relation to the differential contribution of the cerebellum and the striatum to motor skill acquisition: the cerebellum appears to participate in the implementation of anticipatory movements, whereas the striatum may be critically involved in types of motor learning which require a high degree of internal elaboration.     

Zur ‘Regulativen Funktion’ Der Kantischen Antinomien

Ohne ZusammenfassungMein Dank gilt dem Philosoph. Department und dem Institute for the Arts and Humanistic Studies der Pennsylvania State University, die mir in Zusammenhang mit einem dort abgehaltenen Kant-Seminar Gelegenheit zur Ausarbeitung dieses Beitrages gaben.