Short-term and long-term memory deficit following intracarotid Amytal injection: Further support for the memory consolidation hypothesis

To test the three main hypotheses of the human amnesic syndrome (encoding, consolidation, retrieval), we designed an original protocol for memory assessment under Amytal that included, in addition to a retrograde memory measure, both short-term and long-term anterograde memory measures. Twenty epileptic patients with SEEG-confirmed unilateral temporal lobe foci were given right and left injections on successive days. Only the long-term memory measure for material presented under Amytal was significantly related to the presence of a temporal contralateral epileptogenic focus, even if it was assessed when the hemisphere had completely recovered from the effect of Amytal. Short-term memory deficits were observed equally often after injections ipsilateral and contralateral to the epileptogenic focus, and no retrograde amnesia was observed. These results are consistent with the consolidation hypothesis.     

Identifying contours from occlusion events

Surface contours specified by occlusion events that varied in density, velocity, and type of motion (rotation or translation) were examined in four experiments. As a fourth experimental factor, there were both figure-motion trials (the occluding surface moved over a stationary background) and background-motion trials (the background moved behind a stationary surface) in each experiment. Displays contained line patterns and rotary motion (Experiment 1), line patterns and translatory motion (Experiment 2), textured surfaces and rotary motion (Experiment 3), and textured surfaces and translatory motion (Experiment 4). Results indicate that contour identifications are more accurate with translation than with rotation, and that background-motion trials are generally easier than figure-motion trials. Although density in all experiments affected identifications in both background- and figure-motion trials, velocity did so in Experiment 4 only. In Experiments 1, 2, and 3, velocity affected identifications in background-motion trials but not in figure-motion trials. In Experiments 3 and 4, the rate of accretion and deletion of texture was a poor predictor of identification accuracy. These results are not consistent with previous accounts of contour perception from occlusion events, and may reflect an involvement of ocular pursuit as a mechanism for registering contour information.     

Minimodularity and the perception of layout

In natural vision, information overspecifies the relative distances between objects and their layout in three dimensions. Directed perception applies (Cutting, 1986), rather than direct or indirect perception, because any single source of information (or cue) might be adequate to reveal relative depth (or local depth order), but many are present and useful to observers. Such overspecification presents the theoretical problem of how perceivers use this multiplicity of information to arrive at a unitary appreciation of distance between objects in the environment. This article examines three models of directed perception: selection, in which only one source of information is used; addition, in which all sources are used in simple combination; and multiplication, in which interactions among sources can occur. To monocular spatial information, using all combinations of the presence or absence of relative size, height in the projection plane, occlusion, and motion parallax. Visual stimuli were computer generated and consisted of three untextured parallel planes arranged in depth. Three tasks were used: one of magnitude estimation of exocentric distance within a stimulus, one of dissimilarity judgment in how a pair of stimuli revealed depth, and one of choice judgment within a pair as to which one revealed depth best. Grouped and individual results of the one direct and two indirect scaling tasks suggest that perceivers use these sources of information in an additive fashion. That is, one source (or cue) is generally substitutable for another, and the more sources that are present, the more depth is revealed. This pattern of results suggests independent use of information by four separate, functional subsystems within the visual system, here called minimodules. Evidence for and advantages of minimodularity are discussed.     

Effects of fundamental frequency contrast on discrimination and identification of dichotic CV syllables at various temporal delays

Dichotic CV syllables (identical and nonidentical pairs) were presented at nine temporal offsets between 0 and 500 msec. One task consisted in judging quickly whether the syllables in a pair were phonetically the same or different; the other task was to identify both syllables. The fundamental frequency (pitch) of the synthetic stimuli was either the same or different, and either predictable or unpredictable. The pitch variable had surprisingly little effect on the latencies of "same"-"different" judgments, and the expected "preparation" effect of pitch predictability was ba]rely present. Instead, there were strong effects on the frequencies of errors at short temporal delays, which suggests shifts or biases in the phonetic "same"-"different" criterion with context. A comparison with analogous errors in the identification task revealed identical patterns. Further analysis of identification errors showed no overall "feature sharing advantage": The direction of this effect depends on the kind of error committed. Also, a lag effect was found only in nonidentical pairs that received two identical responses. The results are discussed in the framework of a two-stage information-processing model. Effects of pitch are tentatively explained as biases from implicit (pitch) decisions at the auditory level on phonetic decisions in the presence of uncertainty. Four sources of errors are identified: fusion at the auditory level; "integration," confusions, and transpositions at the phonetic level.     

The Vocational Preference Inventory scores and environmental preferences

This study investigated the relationship between vocational interest as measured by the Vocational Preference Inventory and preferences of 175 undergraduates for structured or unstructured environments. Males having clear-cut preferences for structured situations had significantly higher Realistic-Conventional scores than those not having those preferences (p < .05). Additionally, males with structured preferences had significantly lower Social-Artistic scores (p < .025). Results for females were similar, but not statistically significant. Males also had significantly higher (p < .01) Realistic-Conventional scores than females. The significant relationships between VPI scores and preferences for structured and unstructured situations support Holland's contention that interest scores are expressions of personality needs.     

A versatile dispenser for commercial monkey chow reinforcement

A dispenser is described that can deliver a wide variety of foodstuffs of almost any consistency. Despite compact size, storage capacity is sufficient for several days of unattended operation. Computer-compatible logic allows flexible applications in animal housing facilities and experimental setups. Its application in delivering regular monkey chow as reinforcement in experiments is discussed.     

Two strategies in fricative discrimination

Synthetic noises from a [∫]-[s] continuum, followed by vocalic portions that influenced the location of the [∫]-[s] boundary in an identification test, were presented in AXB and fixed-standard AX discrimination tasks. The majority of naive subjects perceived these fricative-vowel syllables fairly categorically in both tasks; that is, discrimination functions followed the patterns predicted from identification scores and showed shifts contingent on the nature of the vocalic portion. However, two subjects achieved much better discrimination scores than the rest, and so did three experienced listeners and a group of less experienced subjects who had received some discrimination training in the AX task. These listeners, who (judging from their higher accuracy, pattern of responses, and subjective reports) successfully followed the nonphonetic strategy of restricting attention to the spectral properties of the fricative noise, were not influenced by different vocalic contexts. These results support the hypothesis that influences of vocalic context on fricative identification are tied to a phonetic mode of perception.     

Developmental aspects of the generation effect

Children from Grades 2, 3, 5, and 7 (7.6, 9, 11, and 13 years of age, respectively) were required to generate or study exemplars of semantic categories (semantic orientation) or rhymes to stimulus words (phonetic orientation). Each child then participated in one of three retention tests: free recall, standard recognition, and rhyme recognition. The results indicated that the developmental emergence of the “generation effect” (C. E. McFarland, Jr., T. J. Frey, & D. D. Rhodes, Journal of Verbal Learning and Verbal Behavior, 1980, 19, 210–225; N. J. Slamecka & P. Graf, Journal of Experimental Psychology: Human Learning and Memory, 1978, 4, 592–604) was dependent on both encoding orientation and the type of retention task employed. A substantial generation effect first emerged (7-year-olds) for standard recognition in the semantic condition. A similar effect for recall was evident for 9-year olds, but not for younger children. Internal stimulus generation became a strong memory facilitator for phonetically encoded items at age 11 for standard recognition, but not until age 13 for recall. The results of the rhyme recognition test indicated that internal generation facilitated “transfer-appropriate processing” (C. D. Morris, J. D. Bransford, & J. J. Franks, Journal of Verbal Learning and Verbal Behavior, 1977, 16, 519–533) only for seventh graders (age 13). The processes underlying this developmental pattern were discussed.     

Relational invariance of expressive microstructure across global tempo changes in music performance: An exploratory study

Summary This study addressed the question of whether the expressive microstructure of a music performance remains relationally invariant across moderate (musically acceptable) changes in tempo. Two pianists played Schumann's Träumerei three times at each of three tempi on a digital piano, and the performance data were recorded in MIDI format. In a perceptual test, musically trained listeners attempted to distinguish the original performances from performances that had been artificially speeded up or slowed down to the same overall duration. Accuracy in this task was barely above chance, suggesting that relational invariance was largely preserved. Subsequent analysis of the MIDI data confirmed that each pianist's characteristic timing patterns were highly similar across the three tempi, although there were statistically significant deviations from perfect relational invariance. The timing of (relatively slow) grace notes seemed relationally invariant, but selective examination of other detailed temporal features (chord asynchrony, tone overlap, pedal timing) revealed no systematic scaling with tempo. Finally, although the intensity profile seemed unaffected by tempo, a slight overall increase in intensity with tempo was observed. Effects of musical structure on expressive microstructure were large and pervasive at all levels, as were individual differences between the two pianists. For the specific composition and range of tempi considered here, these results suggest that major (cognitively controlled) temporal and dynamic features of a performance change roughly in proportion with tempo, whereas minor features tend to be governed by tempo-independent motoric constraints.