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PubMed1999

Perceived hearing aid benefit in relation to perceived needs.

A new scale, the Hearing Aid Needs Assessment (HANA), was developed in order to examine the relationship between perceived communication needs/expectations with the actual benefit eventually achieved with newly fitted hearing aids. A serial sample of 82 patients completed the HANA prior to hearing aid consultation. A subgroup of 42 patients eventually completed the Hearing Aid Performance Inventory after 2 to 3 months of new device use. The results indicated that candidates for amplification expect more benefit than they will typically achieve, especially when listening to speech in noise or without visual cues. For the most part, hearing aid benefit could not be reliably predicted based on perceived need or expectation.

Adult↗
PubMed2000

Independent mechanisms produce visually perceived eye level (VPEL) and perceived visual pitch (PVP).

Two aspects of the perception of extrapersonal space undergo systematic changes with variations in the pitch of the visual environment: (1) the physical elevation perceived to correspond to eye level (VPEL); and (2) the perception of the pitch of the visual environment (PVP). Thus, one might assume that both discriminations are controlled by a common mechanism utilizing visual information from the pitched surface. In fact this assumption has been made frequently, and - in different forms - underlies three substantial but very different historical streams in the literature. A quantitative theoretical development shows that two of these streams, although derived from very different viewpoints and appearing very different themselves (it is assumed that the basis for both PVP and VPEL is information about the pitch of the visual field in one, and information about the location of the subject's eye level within the visual field in the other), make identical predictions: each requires that the weighted sum of PVP and VPEL equal the magnitude of physical pitch and that the weighted sum of their first derivatives equal a constant. The third stream, which assumes that an internal representation of the visual field gives rise to both PVP and VPEL, requires that a weighted difference of PVP and VPEL be proportional to physical pitch and that the weighted difference of their derivatives equal a constant. In an experiment designed to examine the relation between VPEL and PVP, psychophysical measurements of VPEL and PVP were made on 20 subjects across a range of pitches from -30 degrees to +20 degrees. Contrary to the predictions from all three interpretations, we find no significant correlation between the two perceptual variables when the influence of pitch itself is removed, despite the fact that VPEL and PVP each increased systematically with increasing visual field pitch. The results not only rule out the specific predictions derived from all three historical streams, they also rule out any theoretical viewpoint that requires control of both perceptual responses by a single mechanism. The statistical independence between VPEL and PVP implies independence between the mechanisms that give rise to them. The correlation observed here and elsewhere between individual PVP and VPEL settings when the influence of the systematic variation of pitch is not eliminated is a consequence of the way in which variations in the two perceptions are generated experimentally, and not on an identity of the mechanisms mediating the generation of the two perceptual variables themselves.

Adolescent↗
PubMedDate not supplied

Perceived threat and perceived control as predictors of the degree of fear in physical and social situations.

Seventy-one nonclinical subjects indicated their degree of anxiety or fear in response to five physical threat situations and four social threat situations. In addition, for each situation, they rated the probability and consequences of danger or threat generally associated with each situation and the degree of perceived control that they believed they would personally have in each situation. Multiple regressions indicated that only general probability of threat predicted fear in physical situations while the general consequences of threat and the degree of personal control predicted fear in response to social situations.

Adult↗
PubMed1998

Perceived object shape affects the perceived direction of self-movement.

The 'direct-perception' model of heading perception posits that heading is computed directly from optic flow without an intervening structural representation of environmental layout. Here, I give an example in which such a representation is seen to play a role in the interpretation of optic flow. Manipulating the outline of concave objects to give an erroneous percept of convexity caused the perceived direction of heading during a stimulated approach to change as well. Thus, the representation of environmental structure provides the context for using and interpreting image motion.

Form Perception↗
PubMed1977

Perceived lightness depends on perceived spatial arrangement.

The perceived shade of gray depends primarily on the luminance relationship between surfaces percieved to lie in the same plane and not between surfaces that are merely adjacent in the retinal image. This result implies that depth perception must precede lightness perception and that lateral inhibition cannot explain lightness constancy.

Depth Perception↗
PubMed2002

Perceived orientation in physical and virtual environments: changes in perceived orientation as a function of idiothetic information available.

Two experiments examined perceived spatial orientation in a small environment as a function of experiencing that environment under three conditions: real-world, desktop-display (DD), and head-mounted display (HMD). Across the three conditions, participants acquired two targets located on a perimeter surrounding them, and attempted to remember the relative locations of the targets. Subsequently, participants were tested on how accurately and consistently they could point in the remembered direction of a previously seen target. Results showed that participants were significantly more consistent in the real-world and HMD conditions than in the DD condition. Further, it is shown that the advantages observed in the HMD and real-world conditions were not simply due to nonspatial response strategies. These results suggest that the additional idiothetic information afforded in the real-world and HMD conditions is useful for orientation purposes in our presented task domain. Our results are relevant to interface design issues concerning tasks that require spatial search, navigation, and visualization.

Adolescent↗
PubMed2001

Perceived superiority of one's own relationship and perceived prevalence of happy and unhappy relationships.

In a study among 141 Dutch undergraduate students, the participants perceived their relationship on average as better than the relationships of most others, and assumed that a majority was happy and that only a minority was unhappy with their relationship. The higher the relationship satisfaction, the more one considered one's relationship as superior, the higher one estimated the percentage of individuals happy with their relationship, and the lower one estimated the percentage of individuals unhappy with their relationship. Overall, these three perceptions were independently related to relationship satisfaction. However, men's satisfaction was particularly related to the perception that one's own relationship was superior as well as to the assumption that few others were unhappy with their relationship, whereas women's satisfaction was particularly related to the assumption that most others were happy with their relationship.

Adult↗
PubMedDate not supplied

Prediction of patient nonadherence with home-based exercise for cardiac rehabilitation: the role of perceived barriers and perceived benefits.

BACKGROUND: The aim of this study was to determine whether cardiac patients' perceptions of the barriers to and benefits of home exercise while in hospital and 6 weeks after discharge are predictive of nonadherence with regular home exercise 6 months after discharge from hospital. METHODS: A prospective longitudinal study of 459 patients age 75 years or less and discharged from any of six public hospitals in the Lower Hunter Region of New South Wales, Australia, with a diagnosis of acute myocardial infarction or angina was conducted. RESULTS: Multivariate logistic regression analysis, using data provided by 281 (61.2%) patients, showed that cardiac patients' perceptions of the benefits of and the physical environment and time barriers to home exercise while in hospital were predictive of nonadherence with regular home exercise 6 months after discharge from hospital, after adjustment for potential confounders. Six weeks after discharge from hospital, patients' perceptions of the enjoyment and time barriers to home exercise were predictive of nonadherence at follow-up, after adjustment for potential confounders. CONCLUSIONS: Cardiac patients' perceptions of the barriers to and benefits of home exercise may be modifiable sources of nonadherence. A randomized controlled trial is required to confirm and extend upon these findings.

Adult↗
PubMed1995

Chronic pain and depression: role of perceived impact and perceived control in different age cohorts.

Chronic pain adversely affects individuals' physical as well as emotional well-being. A cognitive-behavioral model has been proposed to explain the role of cognitive appraisal variables in mediating the development of emotional distress following pain of long duration. There is little evidence linking the prevalence of depression in chronic pain patients to life stage, but there are suggestions in the literature that the link between medical illness and depression may be stronger in elderly patients. One purpose of this study was to replicate the efficacy of a previous study of the cognitive-behavioral mediation model in explaining the association between pain and depressed affect. A second purpose of this study was to extend the cognitive-behavioral model to evaluate relationships among pain, cognitive appraisal variables, and depressive affect in the elderly chronic pain population. One hundred chronic pain patients were divided into two age groups (< or = 69 years and > or = 70 years). A path analysis conducted for the total sample supported the cognitive-behavioral mediation model of depression in chronic pain, in which cognitive appraisal variables mediate the pain-depression relationship. Correlations among variables in each of the two age groups, however, revealed different patterns of association. Consistent with the cognitive-behavioral model, the younger patients demonstrated a low and non-significant correlation between pain severity and depression (r = 0.01). Conversely, a strong direct association was observed in the older patients between these variables (r = 0.51). These results suggest that the relationship between pain and depression varies substantially depending upon age cohort.

Adaptation, Physiological↗
PubMed1996

Is perceived angular displacement the time integral of perceived angular velocity?

Estimates of rotational self-displacement and self-velocity have been used interchangeably in vestibular psycho-physics to characterize vestibular ego-motion perception. However, the assumption underlying this indiscriminate use has never been tested. The assumption holds that the two estimates are equivalent, with the displacement estimates reflecting the time integral of the signal underlying the velocity estimate. We tested this hypothesis by directly comparing displacement and velocity estimates. Two groups of healthy young subjects (2 x n = 15) were presented with the same vestibular stimuli (horizontal whole body rotations in the dark in the form of velocity steps of 5, 10, 20, and 40 degrees/s with 1, 2, 4, 8, and 16 s duration, yielding position ramps of 5, 10, 20, 40, 80, 160, and 320 degrees total displacement). The first subject group estimated peak velocity, and the second group estimated total displacement, both groups using a comparable psychophysical procedure (Stevens' magnitude estimation). The experimentally obtained velocity estimates were used to predict the displacement estimates. To this end, the velocity signal was assumed to decay exponentially from the reported peak value (reflecting the dynamics of peripheral and early central vestibular mechanisms) and was mathematically integrated. Predicted and measured displacement estimates were similar when a time constant of 20 s was assumed, which is in good agreement with earlier studies. We conclude that vestibular displacement estimates can, indeed, be considered equivalent to vestibular velocity estimates, at least for the stimulus parameters used.

Adult↗
PubMedDate not supplied

Self-perceived distress and self-perceived functional recovery after recent total hip and knee arthroplasty.

The research was aimed at verifying whether psychological distress and depression are associated to reduced functional improvement following arthroplasty. Thirty-six patients with total knee arthroplasty (TKA) and 36 patients total hip arthroplasty (THA) were enrolled at the beginning of their rehabilitation. The mean age in TKA patients was 71.3+/-7.8 years (S.D.). The mean age in THA patients was 67.9+/-8.4 years. The Western Ontario and MacMasters Universities Osteoarthritis Index (WOMAC) and the Hospital Anxiety and Depression (HAD) were applied. Forty-four percent of THA and 58% of TKA showed over-threshold HAD scores at admission. The proportion was even higher considering HAD-Depression sub-scale, where 55% of THA and 61% of TKA patients had over-threshold scores. Lack of depression prompted better functional outcome in TKA. The effect of depression on TKA functional improvement was still significant after adjusting for age and sex. No association was found for THA patients. In order to maximize rehabilitation benefit it is then suggested that patients with recent TKA intervention are screened for distress and depression at admission and that psychological symptoms are treated if over-threshold.

Activities of Daily Living↗
PubMed1997

Comparison between spatial interactions in perceived contrast and perceived brightness.

We examined the spatial integration of simultaneously induced achromatic contrast and compared it to the spatial integration of simultaneously induced brightness. This study extends the work of Zaidi et al. [(1992). Vision Research, 32, pp. 1695-1707], who showed that the total magnitude of induced brightness can be described as the weighted sum of the brightness induced by individual elements of the surround. The results show that contrast induction, though weaker than brightness induction, occurs over greater distances, and that a weighted spatial summation model for contrast induction requires an additional static non-linear compression, which is not required to model brightness induction. The analysis indicates that the contrast compression occurs prior to the lateral interactions that generate induced contrast.

Contrast Sensitivity↗
PubMed2003

Relative influences of perceived parental monitoring and perceived peer involvement on adolescent risk behaviors: an analysis of six cross-sectional data sets.

PURPOSE: To assess: (a) the relative impact of monitoring and peer involvement among six cohorts of African-American youth in their mid-adolescent years, over a decade of research in one urban area, and (b) the consistency of the impact of the two influences over time. METHODS: Baseline data were collected from six cohorts involving 1279 low income African-American youth aged 13 to 16 years involved in community based studies conducted over a decade in an urban area. Self-reported behaviors, and perceptions of parental monitoring and peer risk-involvement were assessed through structured questions. Data were analyzed by frequency distribution, one-way ANOVA, and multiple logistic regression. RESULTS: There was a rapid increase in sexual activity and substance use behaviors during mid-adolescence. Monitoring had a protective influence on substance use behaviors and sexual activity, but had no impact on condom use or drug trafficking. Peer involvement influenced all evaluated risk behaviors. The influences overall did not statistically change over time. CONCLUSIONS: Despite the marked increase in risk behaviors during mid-adolescence, monitoring and peer involvement both influenced adolescent behaviors across each cohort.

Adolescent↗
PubMed1994

Dysphoria as a moderator of the relationship between perceived effort and perceived ability.

Although Heiderian logic (F. Heider, 1958) proposes an inverse relationship between ability and effort, research has uncovered dramatic individual differences in the judged relationship between the two. Some view ability and effort as positively related; others view them as negatively related. Study 1 explored dysphoria as a moderator of this relationship by gathering dysphoric and nondysphoric individuals' perceptions of their effort and ability on daily activities. Although ability and effort generally were positively related, dysphorics reported lower ability on high effort tasks. In Study 2, Ss rated their effort as high or low. Dysphorics discounted ability when effort was high; nondysphorics reported the greatest ability when they expended the greatest effort. Collectively, there was no support for an inverse relationship between ability and effort. However, dysphorics infer less ability than nondysphorics following high effort.

Adult↗