Search results for "imination"
showing 10 items of 605 documents
Color and lightness constancy in different perceptual tasks
1998
Color and lightness constancy with respect to changing illumination was studied with three different perceptual tasks: ranking of colored papers according (1) to their lightness and (2) to their chromatic similarity in photopic, mesopic, and scotopic states of adaptation, and (3) recognition of remembered colored papers after changes of illumination in photopic vision. Constancy was found in the second task, only. Excitations of light receptors and luminance channels were computed to simulate the empirical rank orders. Results of the first task can be predicted with the hypothesis that luminance channels are activated, if lightness is asked for. Sequences arranged with respect to chromatic …
Differences in sensory processing of German vowels and physically matched non-speech sounds as revealed by the mismatch negativity (MMN) of the human…
2014
We compared processing of speech and non-speech by means of the mismatch negativity (MMN). For this purpose, the MMN elicited by vowels was compared to those elicited by two non-speech stimulus types: spectrally rotated vowels, having the same stimulus complexity as the speech stimuli, and sounds based on the bands of formants of the vowels, representing non-speech stimuli of lower complexity as compared to the other stimulus types. This design allows controlling for effects of stimulus complexity when comparing neural correlates of processing speech to non-speech. Deviants within a modified multi-feature design differed either in duration or spectral property. Moreover, the difficulty to d…
Effects of resistance training on testosterone metabolism in younger and older men
2015
This study investigated the effects of resistance training (RT) on the metabolism of testosterone (T) in younger (n=5, 28±3yrs.) and older (n=8, 70±2yrs.) men. Experimental heavy resistance exercises (5×10RM leg presses) were performed before and after a 12-month of RT. No age differences were found in the production or metabolic clearance rate of T (determined by stable isotope dilution method), skeletal muscle androgen receptor content or serum LH concentrations due to acute or chronic RT. The T production capacity response to gonadotropin stimulation and the concentrations of the urinary T metabolites (androsterone and etiocholanolone) were lower in the older compared to younger men (p<0…
The mid-difference hump in forward-masked intensity discrimination
2008
Forward-masked intensity-difference limens (DLs) for pure-tone standards presented at low, medium, and high levels were obtained for a wide range of masker-standard level differences. At a standard level of 25 dB SPL, the masker had a significant effect on intensity resolution, and the data showed a mid-difference hump: The DL elevation was greater at intermediate than at large masker-standard level differences. These results support the hypothesis that the effect of a forward masker on intensity resolution is modulated by the similarity between the masker and the standard. For a given masker-standard level difference, the effect of the masker on the DL was larger for a 55-dB SPL than for t…
Binaural release from masking in forward-masked intensity discrimination: Evidence for effects of selective attention
2012
In a forward-masked intensity discrimination task, we manipulated the perceived lateralization of the masker via variation of the interaural time difference (ITD). The maskers and targets were 500 Hz pure tones with a duration of 30 ms. Standards of 30 and 60 dB SPL were combined with 60 or 90 dB SPL maskers. As expected, the presentation of a forward masker perceived as lateralized to the other side of the head as the target resulted in a significantly smaller elevation of the intensity difference limen than a masker lateralized ipsilaterally. This binaural release from masking in forward-masked intensity discrimination cannot be explained by peripheral mechanisms because varying the ITD l…
Sequential grouping modulates the effect of non-simultaneous masking on auditory intensity resolution.
2012
The presence of non-simultaneous maskers can result in strong impairment in auditory intensity resolution relative to a condition without maskers, and causes a complex pattern of effects that is difficult to explain on the basis of peripheral processing. We suggest that the failure of selective attention to the target tones is a useful framework for understanding these effects. Two experiments tested the hypothesis that the sequential grouping of the targets and the maskers into separate auditory objects facilitates selective attention and therefore reduces the masker-induced impairment in intensity resolution. In Experiment 1, a condition favoring the processing of the maskers and the targ…
Familiarity-based recognition in the young, healthy elderly, mild cognitive impaired and Alzheimer's patients
2009
This study investigates the possible existence of deficits in familiarity in five samples of participants spanning a broad range of ages and cognitive states. Five groups of 16 participants with a diagnosis of multi-domain cognitive impairment with a slight or no deficit in memory, 16 multi-domain amnestic, and 16 Alzheimer's disease patients were compared in a recognition test with equivalent samples of old and young healthy participants. In one of the tests, participants studied words extracted from a restricted set of letters of the alphabet that were later mixed with new words from a different set. The unconscious use of the fluency produced by the repeated use of the set of letters was…
Urinary excretion of heptanones, heptanoles and 2,5-heptanedione after controlled acute exposure of volunteers to n-heptane.
2018
A lack of well-established parameters and assessment values currently impairs biomonitoring of n-heptane exposure. Using controlled inhalation experiments, we collected information on urinary n-heptane metabolite concentrations and the time course of metabolite excretion. Relationships between external and internal exposure were analysed to investigate the suitability of selected metabolites to reflect n-heptane uptake. Twenty healthy, non-smoking males (aged 19-38 years, median 25.5) were exposed for 3 h to 167, 333 and 500 ppm n-heptane, each. Spot urine samples of the volunteers, collected before exposure and during the following 24 h, were analysed for heptane-2-one, 3-one, 4-one, 2,5-d…
Identity, Couple and Intergroup Dynamics in Intercultural Families: Implications on Life Satisfaction of Partners
2019
The current study analyzed how identity, couple, and intergroup dynamics are related to life satisfaction among 210 intercultural partners living in Italy. Three levels of analysis were considered: a micro level, taking into account the identity aspect of each partner in terms of self- or hetero-ethnic identification; a meso level, examining the passion, commitment, and intimacy of the couple sphere of the partners; a macro level investigating the discrimination that partners can perceive by the community as an effect of the relationship between dominant and minority groups. The results show that for both partners, foreign and Italian, the variables that have a predictive value on life sati…
Comparison of olfactory function in patients with seasonal and perennial allergic rhinitis
1998
Hyposmia is a common symptom in allergic rhinitis. However, little is known about differences in the olfactory function of patients with seasonal or perennial allergy. A prospective controlled study was performed on 28 patients with allergic rhinitis to grass pollen and on 47 patients with allergic rhinitis to mites. Sixty-six healthy volunteers served as a control. Olfactory function was evaluated by a modified Connecticut Chemosensory Clinical Research Center testing procedure for threshold, identification, and discrimination. The grass pollen-allergic patients were tested preseasonally and after 3 weeks of intraseasonal grass pollen exposure; the mite-allergic patients and the volunteers…