Neural systems for tactual memories

1. The aim of this study was to investigate the neural systems involved in the memory processing of experiences through touch. 2. Regional cerebral blood flow was measured with positron emission tomography by means of the water bolus H2(15)O methodology in human subjects as they performed tasks involving different levels of tactual memory. In one of the experimental tasks, the subjects had to palpate nonsense shapes to match each one to a previously learned set, thus requiring constant reference to long-term memory. The other experimental task involved judgements of the recent recurrence of shapes during the scanning period. A set of three control tasks was used to control for the type of exploratory movements and sensory processing inherent in the two experimental tasks. 3. Comparisons of the distribution of activity between the experimental and the control tasks were carried out by means of the subtraction method. In relation to the control conditions, the two experimental tasks requiring memory resulted in significant changes within the posteroventral insula and the central opercular region. In addition, the task requiring recall from long-term memory yielded changes in the perirhinal cortex. 4. The above findings demonstrated that a ventrally directed parietoinsular pathway, leading to the posteroventral insula and the perirhinal cortex, constitutes a system by which long-lasting representations of tactual experiences are formed. It is proposed that the posteroventral insula is involved in tactual feature analysis, by analogy with the similar role of the inferotemporal cortex in vision, whereas the perirhinal cortex is further involved in the integration of these features into long-lasting representations of somatosensory experiences.     

The tactual identification of shapes for coding switch handles.

Three experiments concerning the tactual identification of 16 differently shaped lever-switch handles are described. A comparison of the "find" method (S searched through a set to find a particular handle) with the "learn" method (S learned to associate a number with each handle) showed moderate agreement in specifying the predominant confusions and measuring their extent. Change in handle size (from ?-in. to 3/8-in. diameter) had no effect on learning. Two subtests of ten handles selected so as to avoid the predominant confusions were more homogeneous than the original set of sixteen handles, and each subset was learned quickly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selecting behavioral marital interventions: An algorithm for matching couples and treatments.

Presents an algorithm, based on 12 questions, for matching couples and marital interventions. The algorithm can be used to determine the appropriateness of divorce counseling, nonmarital treatments, couples crisis intervention, structured behavior exchange, communication skills training, problem-solving training, marital rule clarification/restructuring, and specific treatment procedures (e.g., sex therapy). (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is the emergence of a right visual field advantage in the category matching task dependent upon category constancy?

Previous research has demonstrated that a right visual field, left hemisphere (RVF-LH) advantage emerges in the second of two blocks of trials where subjects are required to determine if fovcal and peripheral words are exemplars of the same or different categories (Urcuioli etal., 1981, Exp. 2). This effect was obtained when the same words were used in both blocks, as well as when new words from the previously tested categories were introduced in the second block. This finding might be due to a general left hemisphere practice effect, or it might depend upon repeated activation of, and spread of activation within, particular categories in the left hemisphere's semantic system. To evaluate these possibilities, the present study replicated the conditions of Urcuioli et al. and extended them by testing subjects in three blocks rather than two, and by including a condition that involved switching to new words from new categories. The experiment revealed that category constancy is required for the emergence of the RVF-LH advantage. This result is consistent with the spreading activation account for the emergence of the RVF-LH advantage, whereas the practice account received little support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The matching paradigm: An exact test procedure.

Outlines a method for establishing whether a one-to-one pairing configuration between objects in 2 arrays contains more pairings of a particular kind than expected under the null hypothesis, based on rook methodology. The method provides a framework for constructing exact unweighted tests in the matching paradigm and is useful with small samples. Examples illustrating the method are presented. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An automated image-registration technique based on multiple structure matching

A new image-registration technique that matches multiple structures on complementary imaging data sets (e.g., CT and MRI) has been developed and tested with both phantom and patient data. The algorithm assumes a rigid-body transformation and is suitable for correlating structures within the cranium or at the skull base. The basic premise of the new technique is that an optimum transformation is achieved when the relative volume lying outside of the intersection between a structure and its transformed counterpart is a minimum. This relative volume is calculated numerically using a random sampling approach, and a binary searching algorithm was used to step through the nine-dimensional parameter space consisting of three rotation angles, three scaling factors and three components of a translation vector. For the nine tests using phantom data, the automated structure-matching technique was able to predict the correct rotation angles to within +/- 1 degree. The expected clinical performance of the new technique was assessed by comparing results obtained with the new method to those obtained using other techniques for 12 patients who were treated with charged particles at Lawrence Berkeley Laboratory (LBL) and who had image-registration studies performed as part of their treatment plan. For 9 of the 12 patients considered, the new structure-matching technique produced a significantly better registration than the older methods, as measured by the resultant average relative volume lying outside of the intersection between any structure and its transformed counterpart. For the other three patients, results were not significantly different for the new structure-matching method and the older techniques.     

Lateral symmetry in the tactual perception of roughness.

Investigated whether tactual roughness perception is differentially lateralized in the cerebral hemispheres in 3 experiments with 76 18–31 yr old university students. Left- vs right-hand performance in the perception of roughness was assessed using 4 paradigms: unimanual 3-alternative forced choice (3-AFC), dichhaptic 3-AFC, comparative same–different judgment, and magnitude estimation. Results show that Ss consistently performed tactual roughness-perception tasks to an approximately equal degree with the left and right hands in all 4 experimental paradigms. Based on the assumption that equal perceptual performance by the left vs right hand indicates relative equality of the cerebral hemispheres, it is concluded that the tactual perception of roughness is laterally symmetrical in the left and right hemispheres. Findings are discussed in terms of the role of texture in Braille reading and of implications for theoretical and methodological issues in tactual roughness perception. (French abstract) (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between visual and tactual exploration by 6-month-olds.

Observed the looking and touching responses of 48 6-mo-olds to visually or tactually novel objects to investigate the relationship between Ss' visual and tactual exploration. Ss were familiarized with an object of a given color and temperature and were then presented with an object different only in color or different only in temperature. Ss in the temperature-change condition exhibited both visual and tactual novelty responses, whereas Ss in the color-change condition exhibited neither. Findings indicate that 6-mo-olds are capable of tactual recognition memory, temperature is a salient property of objects for infants, and visual exploration and tactual exploration are not independent perceptual activities but are related in an asymmetrical fashion. Findings also support the notion that, in some circumstances, young infants may be so engrossed with the tactual characteristics of an object that attention to its visual properties is diluted. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Consistency of intermanual discrepancies in normal and unilateral brain lesion patients.

Examined the distribution of intermanual discrepancies on 3 motor tests (grooved pegboard, finger tapping, and dynamometer) among 331 normal controls, 63 patients with right brain damage (RBD), and 40 patients with left brain damage (LBD). All Ss were right-handed. Considerable variability in the intermanual discrepancies was observed in all 3 samples. About 25% of the normal sample obtained scores more than 1 standard deviation from the control mean on a single measure. RBD tended to accentuate the pattern of intermanual discrepancies observed with controls, while LBD moved the discrepancy in the opposite direction. Results confirm the difficulties related to clinical judgments of deficits in preferred-hand motor performance and suggest the need to examine patterns of performance across several motor tests. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thinking outside the body: An advantage for spatial updating during imagined versus physical self-rotation.

Three studies examined effects of different response measures on spatial updating during self-rotation. In Experiment 1, participants located objects in an array with a pointer after physical self-rotation, imagined self-rotation, and a rotation condition in which they ignored superfluous sensorimotor signals. In line with previous research, updating performance was found to be superior in the physical self-rotation condition compared with the other 2. In Experiment 2, participants performed in identical rotation movement conditions but located objects by verbal labeling rather than pointing. Within the verbal modality, an advantage for updating during imagined self-rotation was found. In Experiment 3, participants performed physical and imagined self-rotations only and used a pointing response offset from their physical reference frames. Performance was again superior during imagined self-rotations. The results suggest that it is not language processing per se that improves updating performance but rather a general reduction of the conflict between physical and projected egocentric reference frames. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual and tactual perception of shape by young children.

Gave 3-4 yr olds a series of 2-choice matching problems involving visual and/or tactual perception. Contrary to S. A. Rose et al (1972) some shape discriminations were more difficult tactually than visually. Predicted differences between dissimilar and similar discrimination were not obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual versus tactual receptor preference in normal and schizophrenic children.

Receptor preferences between visual or tactual stimuli were measured in schizophrenic and normal children. 4 pairs of standardized choice situations between visual or tactual stimuli were used, with the time of engagement with either stimulus constituting the preference measure. Schizophrenic children, ages 7-9, were compared with same aged normal children. A group of retardates were used for MA control. Schizophrenics were significantly lower in visual preference than the same aged normals, and an age trend for increased visual preference was found in the normal sample. Retardates showed greater visual preference than schizophrenics of comparable MA. Some implications for theory of schizophrenia are discussed. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repetition blindness for words yet repetition advantage for nonwords.

Accuracy of report of words in a rapidly presented sequence is reduced if 1 word is a repetition of a previous word. This is repetition blindness. If, however, the items are pronounceable nonwords, or pseudohomophones, repetition improves recall. A repetition advantage for nonwords also occurs when subjects merely count the items or when the item between the critical nonwords is a familiar word. Familiarizing subjects with the nonwords improved the level of recall but did not affect the repetition advantage. These results are considered in relation to token individuation and other accounts of repetition blindness. The findings suggest that for identical linguistic stimuli the types bound to episodic memory tokens that are vulnerable to repetition blindness are lexical units. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The locus of visual-motor learning at the task or manipulator level: Implications from intermanual transfer.

To assess the functional locus of visual–motor learning, the computational concepts of "task level" programming (determination of the trajectory of a hand during arm reaching in the Cartesian coordinates) and "manipulator level" programming (determination of the joint coordinates) were adopted. Because the former is likely to be hand nonspecific and the latter is hand specific, it is assumed that learning at the task level should be transferred to the unpracticed hand, whereas that at the manipulator level it should not. Under this assumption, the paradigm of intermanual transfer was used in an aiming task under rotated visual feedback. Nearly 100% intermanual transfer from the practiced hand to the unpracticed hand in the performance time of aiming was found, concluding that the locus of visual–motor learning should be at the task level rather than at the manipulator level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clique-detection algorithms for matching three-dimensional molecular structures

MAAGs were introduced as a result of the 1989 White Paper 'Working for Patients', with the remit to direct, coordinate and monitor medical audit activities in general practice. They were funded through the new FHSA management budget and each MAAG was responsible to its own FHSA. They were accepted as a completely new institution as a part of the introduction of an innovative management structure in a reformed NHS. When viewed in an historical context, MAAGs can actually be seen as a part of an expanding culture of greater objectivity and critical analysis which has burgeoned in medical practice over the last two decades. Although MAAGs began with an educational role with uniprofessional medical audit, they have embraced multiprofessional clinical audit in primary care in the context of the wider aspects of quality in practice. The last 20 years have seen the development of clinical guidelines, evidence-based medicine and application of business management theory to clinical quality. All these have reflected the increasing demand for explicit standards of care which has also formed the basis of clinical audit and MAAG activity. MAAGs should be seen as an inevitable concomitant of this historical trend to improve the application of scientific rigour in medical practice. With the adoption of clinical effectiveness, incorporating all these themes, as one of the NHS Executive's six medium-term priority areas, MAAGs are uniquely placed to act as agents of change to enhance the quality of primary health care.     

Laparoscopic surgery for early gastric cancer--its advantage and pitfall

We have successfully treated 50 patients with early gastric cancer by using two different laparoscopic procedures since March 1992. which are laparoscopic wedge resection of the stomach using a lesion-lifting method (n = 33) and laparoscopic intragastric mucosal resection (n = 17). The indication is as follows; (A) mucosal cancer, (B) < 25 mm, if the lesion is protruded type, (C) < 15 mm and Ul(-), if the lesion is depressive type. The advantages of these methods are; 1) minimally invasiveness. 2) sufficient surgical margin, 3) feasibility of detailed histology, 4) feasibility of perigastric lymph node dissection. In contrast, there are several problems to be solved, which are; 1) preoperative diagnostic accuracy of the depth of cancer invasion, 2) possibility of reoperation because of sm invasion or lymphatic or venous invasion in final histology, 3) possibility of postoperative stenosis after laparoscopic intragastric mucosal resection for the lesion near the cardia, 4) incidence of metachronous multiple gastric cancer.