Magnitude estimation: A new method for measuring subjective test variables.

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Download Full-text

Magnitude Estimation and Cross-Modal Matching of Lingual Vibrotactile and Auditory Sensation

Journal of Speech Language and Hearing Research ◽

10.1044/jshr.3203.698 ◽

1989 ◽

Vol 32 (3) ◽

pp. 698-702 ◽

Cited By ~ 2

Author(s):

Daniel Harris ◽

Donald Fucci ◽

Linda Petrosino

Keyword(s):

Auditory Stimulus ◽

Magnitude Estimation ◽

Sensory Processing ◽

Test Site ◽

Systematic Investigation ◽

Thenar Eminence ◽

Stimulus Range ◽

Psychophysical Scaling ◽

Scaling Methods ◽

Response Biases

The present experiment was a preliminary attempt to use the psychophysical scaling methods of magnitude estimation and cross-modal matching to investigate suprathreshold judgments of lingual vibrotactile and auditory sensation magnitudes for 20 normal young adult subjects. A 250-Hz lingual vibrotactile stimulus and a 1000-Hz binaural auditory stimulus were employed. To obtain judgments for nonoral vibrotactile sensory magnitudes, the thenar eminence of the hand was also employed as a test site for 5 additional subjects. Eight stimulus intensities were presented during all experimental tasks. The results showed that the slopes of the log-log vibrotactile magnitude estimation functions decreased at higher stimulus intensity levels for both test sites. Auditory magnitude estimation functions were relatively constant throughout the stimulus range. Cross-modal matching functions for the two stimuli generally agreed with functions predicted from the magnitude estimation data, except when subjects adjusted vibration on the tongue to match auditory stimulus intensities. The results suggested that the methods of magnitude estimation and cross-modal matching may be useful for studying sensory processing in the speech production system. However, systematic investigation of response biases associated with vibrotactile-auditory psychophysical scaling tasks appears to be a prerequisite.

Download Full-text

Temporal-Gap Detection by Cochlear Prosthesis Users

Journal of Speech Language and Hearing Research ◽

10.1044/jshr.3204.849 ◽

1989 ◽

Vol 32 (4) ◽

pp. 849-856 ◽

Cited By ~ 12

Author(s):

John P. Preece ◽

Richard S. Tyler

Keyword(s):

Magnitude Estimation ◽

Stimulus Level ◽

Electrode Placement ◽

Frequency Effect ◽

Gap Detection ◽

Cochlear Prosthesis ◽

Sensation Level

Minimum-detectable gaps for sinusoidal stimuli were measured for three users of a multi electrode cochlear prosthesis as functions of stimulus level, frequency, and electrode place within the cochlea. Stimulus level was scaled by sensation level and by growth-of-loudness functions generated for each condition by direct magnitude estimation. Minimum-detectable gaps decreased with increase in either sensation level or loudness, up to a plateau. When compared at equal sensation levels, the minimum-detectable gaps decreased with frequency increases. The frequency effect on minimum-detectable gaps is reduced if the data are considered at equal loudness. Comparison across place of stimulation within the cochlea showed minimum-detectable gaps to be shorter for more basal electrode placement at low stimulus levels. No differences in minimum-detectable gap as a function of place were found at higher stimulus levels.

Download Full-text