Perceptual constraints in phonotactic learning.

Structural regularities in language have often been attributed to symbolic or statistical general purpose computations, whereas perceptual factors influencing such generalizations have received less interest. Here, we use phonotactic-like constraints as a case study to ask whether the structural properties of specific perceptual and memory mechanisms may facilitate the acquisition of grammatical-like regularities. Participants learned that the consonants C? and C? had to come from distinct sets in words of the form C?VccVC? (where the critical consonants were in word edges) but not in words of the form cVC?C?Vc (where the critical consonants were in word middles). Control conditions ruled out attentional or psychophysical difficulties in word middles. Participants did, however, learn such regularities in word middles when natural consonant classes were used instead of arbitrary consonant sets. We conclude that positional generalizations may be learned preferentially using edge-based positional codes, but that participants can also use other mechanisms when other linguistic cues are given. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual learning in visual search: some evidence of specificities

To test a recent suggestion that perceptual learning in visual search is non-specific, two groups of subjects were trained on visual search tasks and tested for transfer of learning to new tasks. One group was trained on parallel ("pop-out") tasks and transferred to serial, conjunction tasks and the other group trained on conjunction and transferred to pop-out. Some (not all) tasks which are initially serial, rapidly became parallel. Some transfer occurred between the different types of tasks. Under some conditions transfer was either absent or even negative. The specificities observed may reflect the roles of the brain regions involved in learning.     

Perceptual learning style and learning proficiency: A test of the hypothesis.

Given the potential importance of using modality preference with instruction, the authors tested whether learning style preference correlated with memory performance in each of 3 sensory modalities: visual, auditory, and kinesthetic. In Study 1, participants completed objective measures of pictorial, auditory, and tactile learning and learning style self-assessments. The results indicate that objective test performance did not correlate with learning style preference. In Study 2, the authors examined in more detail the information participants used to answer the learning style self-assessment. The findings indicate that participants answered the inventory using general memories and beliefs rather than specific examples of learning in different modalities. These results challenge the hypothesis that individuals learn best with material presented in a particular sensory modality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual learning in visual search: fast, enduring, but non-specific

Visual search has been suggested as a tool for isolating visual primitives. Elementary "features" were proposed to involve parallel search, while serial search is necessary for items without a "feature" status, or, in some cases, for conjunctions of "features". In this study, we investigated the role of practice in visual search tasks. We found that, under some circumstances, initially serial tasks can become parallel after a few hundred trials. Learning in visual search is far less specific than learning of visual discriminations and hyperacuity, suggesting that it takes place at another level in the central visual pathway, involving different neural circuits.     

Hospital controls versus community controls: differences in inferences regarding risk factors for hip fracture

In cranioplasty complexity is proportional to the size of the detect, particularly if greater than 50 cm2. If the patient's own bone flap is not available, allogenic frozen bone graft can be used instead. Between June 1990 and June 1995 twenty cranioplasties with allogenic frozen bone grafts were performed. Age of patients ranged between 23 and 63 years (average 38.4 years). Male/female ratio was 2:1.7. Size of craniectomy ranged between 65 and 150 cm2 (average 83.3 cm2). Follow-up ranged between 10 and 58 months (average 41 months). Donors were tested to rule out transmissible diseases, infections, sepsis and/or cancer. Bone grafts were removed under aseptic conditions, microbiological cultures were taken, wrapped in a gauze soaked with Gentamicin sulphate and Bacitracin, sealed in three sterilised vinyl plastic bags, and stored in a deep freezer for a minimum of 30 days (range 36-93 days, average 67 days), at a temperature of -80 degrees C. Grafts were placed in the defect after a step was carved on its borders to facilitate the contact between host and graft. Vancomycin 1 g. IV/12 hours and Ceftriaxone 1 g. IV/12 hours were administered for five days. Grafts were covered by means of scalp flaps. Only one required a musculocutaneous free flap. None was exposed, extruded or had to be removed. Plain skull X-ray studies showed progressive remodelling of the grafts. Partial resorption was observed in two (2/20, 10%) and loss of thickness in another 3/20 (15%), but with no changes in the contour. Biopsies were taken in 3/20 (15%) cases at a second surgical procedure. Areas of osteoclastic resorptive activity mixed with others of osteoblastic bone apposition, showed replacement with new bone. We conclude that cranial vault frozen allografts are a good alternative to autologous bone when the latter is absent or not present in sufficient amount.     

Perceptual learning in flavor aversion: Evidence for learned changes in stimulus effectiveness.

Rats were exposed to the compound flavors AX and BX, presented in alternation, and to CX on a separate block of trials. Generalization to BX after aversion conditioning with AX was less than to CX. An equivalent effect was found when the nature of the common element was changed after preexposure but not when the common element was omitted during preexposure, during conditioning and test, or both. Rats conditioned with X alone again showed less aversion to BX than to CX; similarly, rats conditioned with a novel flavor (Y) showed less aversion to BY than to CY. These effects support the proposal that intermixed preexposure to AX and BX enhances the perceptual effectiveness of their unique features, A and B. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual learning of spatiotemporal events: Evidence from an unfamiliar modality.

Perceptual learning was examined in two experiments in which subjects, originally unfamiliar with vibrotactile stimulation, were required to identify dynamic vibrotactile patterns with static visual patterns of the same two-dimensional shapes. In Experiment 1 we examined changes in performance with practice under a variety of vibrotactile spatial and temporal conditions. In Experiment 2 we investigated transfer of learning from one set of vibrotactile patterns to another different set. In neither experiment were subjects supplied with knowledge of results. Substantial perceptual learning (improvement in identification with practice) was observed in Experiment 1, although a minority of subjects did not exhibit improvement. Experiment 2 confirmed the general findings of Experiment 1 and also provided evidence of substantial positive transfer. In both experiments, multidimensional scaling of pattern confusion data revealed that practice (and improvement in identification) did not qualitatively change the relative confusability of patterns, suggesting that the (informative) structure of the patterns, irrespective of familiarity with a specific set of patterns, determined confusability. The findings are interpreted in terms of learning constructs offered by E. J. and J. J. Gibson. We conclude by considering the prospects that a connectionist mechanism can account for the observed perceptual learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual learning of noise vocoded words: Effects of feedback and lexicality.

Speech comprehension is resistant to acoustic distortion in the input, reflecting listeners' ability to adjust perceptual processes to match the speech input. This adjustment is reflected in improved comprehension of distorted speech with experience. For noise vocoding, a manipulation that removes spectral detail from speech, listeners' word report showed a significantly greater improvement over trials for listeners that heard clear speech presentations before rather than after hearing distorted speech (clear-then-distorted compared with distorted-then-clear feedback, in Experiment 1). This perceptual learning generalized to untrained words suggesting a sublexical locus for learning and was equivalent for word and nonword training stimuli (Experiment 2). These findings point to the crucial involvement of phonological short-term memory and top-down processes in the perceptual learning of noise-vocoded speech. Similar processes may facilitate comprehension of speech in an unfamiliar accent or following cochlear implantation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ventromedial prefrontal damage and memory for context: Perceptual versus semantic features.

Memory for context is known to rely on episodic binding and strategic retrieval processes. It is unclear, however, whether memory for different contextual features taps the same cognitive and neural mechanisms. Here, the authors compare memory for a perceptual feature (i.e., the format in which an item had been presented) and for a semantic feature (i.e., the concept with which an item had been paired) in 13 patients with lesions in ventromedial prefrontal cortex, including patients with and without confabulation, and 13 healthy controls. Participants studied picture–word pairs and received an old–new recognition test that included intact pairs, rearranged pairs, format pairs (studied pairs in which the picture–word format of each item was switched), old–new pairs, and new–new pairs. Hit rates for intact pairs were similar for all participant groups. Compared with controls, patients, especially those with confabulation, had higher false-alarm rates for format pairs but comparable false-alarm rates for rearranged pairs. The authors propose that distinct monitoring processes are engaged during retrieval of perceptual and semantic context, with only the former crucially dependent on ventromedial prefrontal cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual learning of spatial localization: specificity for orientation, position, and context

Discrimination of simple visual attributes can improve significantly with practice. We have trained human observers to perform peripherally presented tasks involving the localization of short line segments and examined the specificity of the learning for the visual location, orientation, and geometric arrangement of the trained stimulus. Several weeks of training resulted in dramatic threshold reductions. The learning was specific for the orientation and location of the trained stimulus, indicating the involvement of the earliest cortical stages in the visual pathway where the orientation and location of stimuli are mapped with highest resolution. Furthermore, improvement was also specific for both the configuration of the trained stimulus and the attribute of the stimulus that was under scrutiny during training. This degree of specificity suggests that the learning cannot be achieved by cortical recruitment alone, as proposed in current models, but is likely to involve a refinement of lateral interactions within the cortex and possibly a gating of lower level changes by attentional mechanisms.     

Individual differences in learning: Visual versus auditory presentation.

Investigated the possible interaction of individual differences in learning with mode of presentation. Ss were college students; data analyses were replicated by conducting separate analyses for 2 groups of 77 and 83 Ss, respectively. Each S learned 4 test lists of 20 words each, 2 under auditory and 2 under visual presentation. The main analyses indicated that individual differences in learning were reliable and that individual differences were just as predictable across as within modalities. A complementary analysis showed that Ss could not be reliably classified in terms of auditory–visual preference scores. The findings give no support to the contention that Ss can be classified as auditory learners or visual learners. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responses to quantity: Perceptual versus cognitive mechanisms in chimpanzees (Pan troglodytes).

Two chimpanzees were trained to select among 2 different amounts of candy (1–6 items). The task was designed so that selection of either array by the active (selector) chimpanzee resulted in that array being given to the passive (observer) animal, with the remaining (nonselected) array going to the selector. Neither animal was able to select consistently the smaller array, which would reap the larger reward. Rather, both animals preferentially selected the larger array, thereby receiving the smaller number of reinforcers. When Arabic numerals were substituted for the food arrays, however, the selector animal evidenced more optimal performance, immediately selecting the smaller numeral and thus receiving the larger reward. These findings suggest that a basic predisposition to respond to the perceptual motivational features of incentive stimuli can interfere with task performance and that this interference can be overridden when abstract symbols serve as choice stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approaches to empathy training: Programmed methods versus individual supervision and professional versus peer supervisors.

Examined the effects of training method (programmed vs individual supervision) and supervisor experience (peer vs professional) on the learning of empathy. Eight supervisors (4 professional and 4 peer) were assigned 3 Ss in each of 3 groups: individually supervised, programmed, and control. Ss listened to 3 sets of recorded client statements and responded as counselors. The 2 experimental groups received training after the 1st and 2nd sets. The control group received no training. An analysis of recorded responses indicated that the individually supervised Ss achieved a significantly higher level of empathy than the controls. Ss receiving programmed training were intermediate in learning between individually supervised and control Ss. Supervisor experience was not found to be a significant factor as no posttraining differences were noted between professional and peer-trained groups. This result supports the use of peers in such interpersonal skills training. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigating preservice teachers' professional growth in self-regulated learning environments.

Educational reforms have suggested that the ability to self-regulate learning is essential for teachers' professional growth during their entire career as well as for their ability to promote these processes among students. This study observed teachers' professional growth along 3 dimensions: self-regulated learning (SRL) in pedagogical context, pedagogical knowledge, and perceptions of teaching and learning. The authors examined 194 preservice teachers' professional growth in 4 learning environments: e-learning (EL) and face-to-face (F2F) learning, either supported by SRL (EL + SRL; F2F + SRL) or unsupported by SRL (EL; F2F). SRL support was based on the IMPROVE metacognitive self-questioning method (B. Kramarski & Z. R. Mevarech, 2003). Mixed quantitative and qualitative analyses showed that preservice teachers in both supported SRL conditions outperformed their unsupported peers on all professional growth measures. Moreover, EL + SRL teachers exhibited the highest SRL ability (cognition, metacognition, motivation), pedagogical knowledge (designing a learning unit), and student-centered learning perceptions (self-construction of knowledge). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of selective attention: Perceptual load influences early versus late attentional selection in children and adults.

The moderating effect of perceptual load on visual selective attention was examined in 2 studies. In Study 1, children and young adults searched displays of varying set size flanked by irrelevant distractors. Children's performance was as efficient as adults' under conditions of high but not low loads, suggesting that early selection engages rapidly maturing neural systems and late selection engages later-maturing systems. In Study 2, 4 age groups were tested, and place markers were set at empty locations to examine perceptual grouping effects. Study 1's pattern was replicated in all age groups, with onset of early selection occurring at lower loads for younger children. Overall, children initiated early selection at lower loads to compensate for immature anterior-system interference control processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social learning family therapy versus parent training: Inconclusive.

Comments that methodological and interpretive issues raised by a study of a behavioral therapy program for aggressive behavior in elementary-school boys by T. V. Sayger et al (see record 1989-12762-001) limit conclusions about the effectiveness of the treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in learning serial patterns: Direct versus indirect measures.

Adult age differences in learning and retention of a nonverbal sequence were examined using the serial reaction-time (RT) task of M. J. Nissen and P. Bullemer (see record 1987-13436-001), with 20 younger and 20 older Ss. An asterisk appeared in one of 4 spatial locations, and the Ss responded with a corresponding key press. The first 4 blocks each contained 10 repetitions of a 10- or 16-element spatial sequence, and the 5th block contained a random sequence. The difference between response time on Blocks 5 and 4 served as an indirect measure of pattern learning. The direct measure was accuracy in a final generation block in which the Ss predicted which location would appear next. Results were similar to those with verbal materials; the indirect measure revealed age similarity for patterns of both lengths, but the direct measure yielded age differences favoring the young. For both ages and types of measures, the long patterns led to poorer learning than did the short patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quality of life following third molar removal: a patient versus professional perspective

We report a case of pleomorphic adenoma with extensive squamous metaplasia in the palate of a 52-year-old Chinese man. The dimensions of the tumor were 15 x 13 x 13 mm. More than 95% of the epithelial element in the tumor was composed of sheets of squamous cells with cyst formation. The pathogenesis, potential diagnostic pitfalls, proliferative activity and cytokeratin expression of this tumor are discussed.     

Developing a comparative measure of the learning climate in professional schools.

Developed the Learning Climate Questionnaire (LCQ) to assess the learning climate of professional schools. 7 populations of students from 4 business schools and 1 nonbusiness professional school participated in this study (N = 455). 5 factors were extracted from the LCQ (Grading Process, Physical Environment, Task Relationships with Faculty, Social Relationships with Faculty, and Course Material Presentation) which were fairly independent (average intercorrelations = .33) and had high internal consistency (average a = .84) across all samples. Comparisons of the objective properties of the schools and measures of overall student satisfaction with the LCQ factors suggest considerable validity of the instrument. Consequently, it seems appropriate to utilize the LCQ for substantive research investigations into the organizational dynamics of professional schools. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)