Search results for "perception"
showing 10 items of 3634 documents
Olfactory Dysfunction After Head Injury
2008
Objective: To determine the incidence of olfactory dysfunction after head trauma using clinical and radiologic findings, quantitative assessment, and electro-physiologic methods. Participants: A total of 190 patients with head trauma of different severity (n = 32 with mild traumatic brain injury (TBI), n = 94 with signs of moderate TBI, and n = 64 with severe TBI) 6 to 32 months prior to the study. Design: Patients were selected retrospectively, surveyed by telephone (n = 190), and screened for olfactory function with Brief Smell Identification Test (n = 82). Those with olfactory dysfunction were assessed as outpatients using the Sniffin' Sticks (n = 19) and olfactory-evoked potential recor…
Differentiating the differential rotation effect.
2011
As an observer views a picture from different viewing angles, objects in the picture appear to maintain their orientation relative to the observer. For instance, the eyes of a portrait appear to follow the observer as he or she views the image from different angles. We have explored this rotation effect, often called the Mona Lisa effect. We report three experiments that used portrait photographs to test variations of the Mona Lisa effect. The first experiment introduced picture displacements relative to the observer in directions beyond the horizontal plane. The Mona Lisa effect remained robust for vertical and/or diagonal observer displacements. The experiment also included conditions in …
Testing the egocentric mirror-rotation hypothesis.
2011
AbstractAlthough observers know about the law of reflection, their intuitive understanding of spatial locations in mirrors is often erroneous. Hecht et al. (2005) proposed a two-stage mirror-rotation hypothesis to explain these misconceptions. The hypothesis involves an egocentric bias to the effect that observers behave as if the mirror surface were rotated by about 2° to be more orthogonal than is the case. We test four variants of the hypothesis, which differ depending on whether the virtual world, the mirror, or both are taken to be rotated. We devised an experimental setup that allowed us to distinguish between these variants. Our results confirm that the virtual world — and only the v…
For the mind's eye the world is two-dimensional.
2010
The nature of visual mental images is a topic that has puzzled neuroscientists, psychologists, and philosophers alike. On the one hand, mental images might preserve the 3-D properties of our perceptual world. On the other hand, they might be akin to 2-D pictures, such as photographs, paintings, or drawings. In the present study, 16 observers judged where real objects (Experiment 1) or photographs thereof (Experiment 2) were pointing. Both experiments contained a perception condition and an imagery condition. In Experiment 1, there was a significant difference between the pointing errors in the perception and the imagery conditions, whereas there was no such difference in Experiment 2. In im…
Variability of human saliva composition: possible relationships with fat perception and liking
2012
International audience; Saliva is the medium that bathes the taste receptors in the oral cavity and in which aroma and taste compounds are released when food is eaten. Moreover saliva contains enzymes and molecules that can interact with food. To date, little research has been devoted to the intra- and inter-individual variabilities of these components and their inter-relationships. The first aim of this work was to study intra- and inter-individual variabilities over time in the composition of molecules likely to interact with food in the mouth, with particular focus on molecules that might interact with fat. The second aim was to try to relate this composition to a liking for fat and its …
Model cheese aroma perception is explained not only by in vivo aroma release but also by salivary composition and oral processing parameters
2017
This advance article is part of themed collection: Structure & Sensory.; International audience; The aim of the present paper was to determine, from four model cheeses differing in fat content and firmness and consumed by fourteen well characterised subjects, the respective impacts of in vivo aroma release, bolus rheology, chewing activity, mouth coating and salivary composition on dynamic aroma perception. The originality of the approach is that it considers all the parameters together and is able to evaluate their relative contribution using multi-block partial least square (MB-PLS) regression. The fruity aroma perception of the more hydrophilic compound (ethyl propanoate) was related to …
Evidence for gesture-speech mismatch detection impairments in schizophrenia.
2019
Patients with schizophrenia suffer from impairments in the perception and production of gestures. The extent to which patients can access the semantic association between speech and co-verbal gestures in concrete or abstract/metaphorical meaning contexts is unknown. We investigated 1) how patients differ from controls in gesture matching performance, 2) how performance differs in the context of abstract versus concrete meaning, and 3) whether formal thought disorder (FTD) symptom severity predicts task impairment. Forty-five patients with schizophrenia spectrum disorders (two subgroups, mild and severe) took part in this study. Participants were presented with video clips, each showing an a…
Motor Activity Improves Temporal Expectancy
2015
International audience; Certain brain areas involved in interval timing are also important in motor activity. This raises the possibility that motor activity might influence interval timing. To test this hypothesis, we assessed interval timing in healthy adults following different types of training. The pre- and post-training tasks consisted of a button press in response to the presentation of a rhythmic visual stimulus. Alterations in temporal expectancy were evaluated by measuring response times. Training consisted of responding to the visual presentation of regularly appearing stimuli by either: (1) pointing with a whole-body movement, (2) pointing only with the arm, (3) imagining pointi…
Factors limiting performance in a multitone intensity-discrimination task: disentangling non-optimal decision weights and increased internal noise.
2013
To identify factors limiting performance in multitone intensity discrimination, we presented sequences of five pure tones alternating in level between loud (85 dB SPL) and soft (30, 55, or 80 dB SPL). In the "overall-intensity task", listeners detected a level increment on all of the five tones. In the "masking task", the level increment was imposed only on the soft tones, rendering the soft tones targets and loud tones task-irrelevant maskers. Decision weights quantifying the importance of the five tone levels for the decision were estimated using methods of molecular psychophysics. Compatible with previous studies, listeners placed higher weights on the loud tones than on the soft tones i…
Self-Reported versus Measured Height, Weight and Body Mass Index in Spanish Mediterranean Teenagers: Effects of Gender, Age and Weight on Perceptual …
2002
<i>Background:</i> To have a good physical appearance is a determining factor by which adolescents show a tendency to worry excessively about their weight. The aim of this work is to study the possible relationship between actual and perceived body weight, how it is considered and what strategies are followed for weight control among adolescents residing in Valencia. <i>Methods:</i> A sample of 568 students, 325 girls and 243 boys, aged 14–20 years, were selected from public high schools in Valencia. Their height and weight were used to calculate their actual body mass index (BMIO). The subjective perception of their physical measurements (BMIS) was evaluated by mean…