Apple slide tachistoscope

We outline a BASIC program and subsidiary machine language timing routines that enable the Apple II series of computers to be employed as control devices for the tachistoscopic presentation of 35-mm slides and the collection of response latencies. The program is functional for experiments that require pictorial stimuli to be presented in up to three separate fields, with precise display times, precise interstimulus and intertriai intervals, and the collection of manual or vocal reaction times with millisecond accuracy. The major advantages of this system are that initial setup costs are substantially lower than those for other similar systems (e.g., Loftus, Gillispie. Tigre, & Nelson, 1984) and that user customization of the program may be accomplished by anyone possessing rudimentary knowledge of the BASIC programming language.     

Interactive braille output for blind computer users

Blind readers were tested using two methods of reading text displayed by an Apple microcomputer. The first method employed an Optacon system, a device that displays tactile representations of single characters, and the second used an interactive single electronic braille cell that displayed grade 1 braille characters. The results demonstrated no difference in accuracy or reading speed between these two methods. Thus, the serial presentation of braille characters at a single position appears to be a viable method of information transfer between computers and braille readers.     

Binaural interaction in backward masking

The binaural auditory system exhibits certain advantages over the monaural system when detecting a tonal signal in a background of masking noise. These advantages have been described in detail and are referred to as masking-level differences, or MLDs. It has been demonstrated, for example, that performance in detecting a tonal signal that has been reversed in phase at one ear relative to the other ear is about 15–17 dB better than detection of the same signal in-phase at the two ears when masked by moderately intense masking noise that is in-phase at the two ears. The explanations for this phenomenon fall into two general categories, and both types of explanations are based upon the interaction of the tonal signal and masker when they are added together. In the present paper, data are presented which indicate that an MLD of at least 4–5 dB can be obtained in a binaural masking experiment in which the offset of the tonal signal precedes the onset of the noise masker.     

Effect of “backward” masker fringe on the detectability of pulsed diotic and dichotic tonal signals

The effects of backward masker “fringe” on performance in homophasic and antiphasic masking conditions were investigated. The results of the study indicate that (1) the presence of a backward masker fringe has only a small effect on performance in homophasic masking conditions; (2) under antiphasic masking conditions, the presence of a backward masker fringe improves performance; (3) similar to the results of studies investigating the effects of forward masker fringe, the magnitude of the improvement in performance increases as the duration of the fringe increases; and (4) the magnitude of the improvement caused by the presence of backward masker fringe is considerably smaller than the magnitude of the improvement caused by the forward masker fringe. It appears, then, that the presence of backward masker fringe may provide a baseline or reference phase similar to that which the forward fringe is presumed to provide. The presence of this reference phase after the offset of the signal apparently makes the phase shift associated with the signal-plus-noise waveform more discernible, thus leading to higher detectability. However, for reasons not yet clear, the presence of a baseline or reference phase after the offset of the signal (backward fringe conditions) does not make the signal-plus-noise phase shift as discernible as do either the presence of that same reference phase before the onset of the signal (forward fringe condition) or the presence of that same reference phase both before signal onset and after signal offset (continuous masker condition).     

WHY A BRAIN CAPABLE OF LANGUAGE EVOLVED ONLY ONCE: PREFRONTAL CORTEX AND SYMBOL LEARNING

Abstract. Language and information processes are critical issues in scientific controversies regarding the qualities that epitomize humanness. Whereas some theorists claim human mental uniqueness with regard to language, others point to successes in teaching language skills to other animals. However, although these animals may learn names for things, they show little ability to utilize a complex framework of symbolic reference. In such a framework, words or other symbols refer not only to objects and concepts but also to sequential and hierarchical relationships with other symbols. This process is essential to human mental operations, including language, mathematics, and music. In humans, these operations may have coevolved with the prefrontal area of the cerebral cortex, which is proportionately much larger in humans than in other animals and more intricately linked with other areas of the brain. Analysis of the structure and function of the prefrontal area suggests that it is centrally involved in the operation of higher-order associative relationships involving the subordination of one set of associations to another. This alternate learning strategy apparently appeared at the cost of certain sensory, motor, or limbic abilities. The payoff was symbolic thinking. Humans thus are unique among species, not just for their highly developed language ability but for their odd style of thinking and learning.     

Mental shock can produce retrograde amnesia

Subjects in three experiments saw a short film of a mentally shocking event in which a young boy is violently shot in the face. Compared to other subjects who saw a nonviolent version of the same film, those who saw the mentally shocking version showed poorer retention of the details of the film. Retention was poorer whether measured by recognition or recall. Furthermore, impaired memory occurred only when the event was mentally upsetting, and not when it was merely unexpected but not upsetting. These results suggest that mentally shocking episodes may disrupt the lingering processing necessary for full storage of information in memory.     

THE REDUCTION OF STEALING IN SECOND GRADERS USING A GROUP CONTINGENCY1

Three classes of second graders served as subjects in this study of the effects of two types of intervention programs upon stealing: (1) an antistealing lecture with no specific contingency implied, and (2) a direct group contingency applied, whereby children were rewarded with (a) extra free time for no thefts, (b) allowed normal free time if stolen items were returned, and (c) punished with loss of free time if stolen items were not returned. A multiple-baseline design across the three classes showed the group contingency to be effective in reducing stealing behavior; the anti-stealing lecture was ineffective.     

Monkey homologues of language areas: computing the ambiguities

The 'language-readiness' of human brains most probably resulted from modification of structures present in non-human primate brains, but identifying such homologues and the nature of their modifications has been highly problematic. In a recent article, Arbiband Bota suggest that these problems can be overcome using a neuroinformatics approach. But its assumptions ignore many non-local, activity-dependent, regressive, and allometric effects of neurodevelopment that violate assumptions of classic homology. What if these effects are what matter most?     

Happy affect and smiling: is their relation moderated by interpersonal power?

Three studies examined the hypothesis that the relation between self-rated happy affect and overall smiling during dyadic interactions is moderated by one's relative power. In all 3 studies, interpersonal power was experimentally manipulated, and smiling and self-reported happy affect were measured during and after the interaction, respectively. Happy affect was positively correlated with overall smiling for both low-power and high-power participants. Moreover, the correlations for both low- and high-power participants were comparable to those found when power roles were not unequal or made salient, based on analysis of the present studies as well as comparison with the previously published literature. Happy affect and overall smiling had a positive relation that was not moderated by interpersonal power.