Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 7069055

Detection threshold microstructure and its effect on temporal integration data.

M F Cohen
View original source ↗Export metadata ↓

Abstract

Auditory detection thresholds were measured at several preselected frequencies using an adaptive 2IFC procedure. Results confirm the existence of shifts in detection threshold ranging from 2 to 14 dB with quite small changes in signal frequency. There does not appear to be a uniform pattern associated with the microstructure of the detection threshold curve. An additional experiment was performed to determine the effect of signal duration on detection threshold microstructure. Results indicate that the temporal integration function is considerably steeper for more sensitive frequencies (3.7 dB/doubling of duration), than for less sensitive frequencies (1.7 dB/doubling). This probably is not due to differences in processing as much as it is to the effect of the energy spread associated with decreasing signal duration.

Explore related subjects

Acoustic StimulationAuditory ThresholdHumansPsychoacousticsJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M F Cohen. 1982. Detection threshold microstructure and its effect on temporal integration data.. https://doi.org/10.1121/1.387442

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1995

Magnetic resonance elastography by direct visualization of propagating acoustic strain waves.

A nuclear magnetic resonance imaging (MRI) method is presented for quantitatively mapping the physical response of a material to harmonic mechanical excitation. The resulting images allow calculation of regional mechanical properties. Measurements of shear modulus obtained with the MRI technique in gel materials correlate with independent measurements of static shear modulus. The results indicate that displacement patterns corresponding to cyclic displacements smaller than 200 nanometers can be measured. The findings suggest the feasibility of a medical imaging technique for delineating elasticity and other mechanical properties of tissue.

Acoustic Stimulation↗
PubMed1995

Possible modulation of auditory middle latency responses by nitric oxide in the inferior colliculus of anaesthetized rats.

Nitric oxide (NO) is a short-lived radical species endowed with intercellular signalling functions in the mammalian brain. In the present study we have investigated the effects of focal injection into one inferior colliculus of N omega-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, on the acoustic middle latency responses (MLRs) evoked by click stimuli and recorded from the auditory cortex in anaesthetized rats. Microinfusion of L-NAME (1.0 mM) did not alter the latency of MLRs nor did it affect the evoked brain stem responses (ABRs). By contrast, L-NAME reduced P1a-N1 amplitude of MLRs by 51.7 +/- 6.6% (mean +/- SEM; n = 5) and almost complete recovery to background amplitude was obtained 15-25 min after treatment. The less active isomer, D-NAME (1.0 mM; n = 5), failed to produce consistent effects on the evoked MLRs. A higher concentration of L-NAME (5.0 mM; n = 5) yielded a 69.0 +/- 13.3% inhibition whereas maximum inhibition produced by 0.5 mM (n = 3) L-NAME was approximately equal to 10% of control value. The inhibitory effect typically evoked by 1.0 mM L-NAME was prevented by treating rats with L-arginine (5.0 mM; n = 5), the endogenous precursor of NO synthesis. Reduction of MLR amplitude was also obtained in rats receiving intracollicular injection of dizocilpine (MK801; 1.0 microM) and LY274614 (1.0 mM), two selective N-methyl-D-aspartate (NMDA) receptor antagonists. In conclusion, the present data support a role for intracollicular NO in the processing and transmission of the acoustic input to the auditory cortex in the rat.

Acoustic Stimulation↗
PubMed1995

Double dissociation of conditioning and declarative knowledge relative to the amygdala and hippocampus in humans.

A patient with selective bilateral damage to the amygdala did not acquire conditioned autonomic responses to visual or auditory stimuli but did acquire the declarative facts about which visual or auditory stimuli were paired with the unconditioned stimulus. By contrast, a patient with selective bilateral damage to the hippocampus failed to acquire the facts but did acquire the conditioning. Finally, a patient with bilateral damage to both amygdala and hippocampal formation acquired neither the conditioning nor the facts. These findings demonstrate a double dissociation of conditioning and declarative knowledge relative to the human amygdala and hippocampus.

Acoustic Stimulation↗