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Visual properties of neurons in the prelunate visual area
S210 RESPONSE PROPERTIES TO DIFFERENT FACIAL
OF SINGLE FEATURES
NEURONS
IN T H E
INFEROTEMPORAL
CORTEX
OF T H E
MONKEY
SHIGERU YAMANE*, SHINJI KAJ!, AND KENJI KAWANO Electroteehnical Laboratory, Umezono, Tshukubashi, Ibarakiken 305, Japan Single neurons were recorded in the inferotemporal cortex (IT) of a monkey trained to discriminate three selected human faces from a large number of different faces (Neurosci. Res., s5, s114, 1987). We used 30 faces, a square and an ellipse as the discrimination stimuli, and also a small green spot that appeared after a stimulus disappeared to determine whether the monkey discriminated the stimulus or not. We examined 446 single neurons in the anterior and posterior banks of the superior temporal sulcus, including its fundus, and the gyrus of the IT. Of the 446 neurons, there were 86 face-responsive neurons. Most of them responded also to the green spot (41/86), and the square and/or the ellipse (24/86). These neurons were found in all regions. Out of 86 neurons, only 21 responded exclusively to the faces, and most of them (18/21) were located in the gyrus of the IT. Faces used as stimuli were quantified by measuring the distances between individual parts of the face e.g., eyes, eyebrows, nose, mouth, hair, etc. The correlation analysis between the quantified facial features and the response magnitudes gave correlation coefficients greater than 0.6 for five out of the 21 face-responsive neurons. Responses of these neurons correlated to the combined distances between the different parts of the faces. One of them showed correlated responses to the combination of the degree that the forehead above the left eye was covered with hair and the distance between the eyes and the mouth. In order to confirm that the neuron detected the combined facial features, six montaged faces made up of two faces, i.e., one face that excited and another that inhibited the neuron, were used as the stimuli. The relationships between the responses of this neuron to the montaged faces and the combined facial features were close to the regression line obtained from the correlation analysis. It is concluded that this neuron detected the combination of the degree that the forehead was covered with hair and the distance between the eyes and the mouth. The fact that the neuron detected essential features to faces confirms that the neuron belongs to face neurons. All of the face-responsive neurons that responded also to the square or the ellipse showed a correlation coefficient of less than 0.6 in our analysis.
VISUAL PROPERTIES OF NEURONS IN THE PRELUNATE VISUAL AREA.
TANAKA M A S A F U M I , C R E U T Z F E L D T OTTO D E T L E V *+, Dept. of A e r o s p a c e Physiology, Res. Inst. of Environmental Medicine., Nagoya Univ., Furo-cho, Chikusa-ku, Nagoya 464, TDept. of Neurobiology, Max-Planck Inst. for biophysical chemistry, P.O. Box 2841, 3400 Gottingen, F. R. Germany. We recorded a c t i v i t i e s from single neuron units in the p r e l u n a t e gyrus of two a w a k e m o n k e y s ( M a c a c a sylvana). recording sessions.
The m o n k e y s
w e r e divided into four groups: neurons.
w e r e trained to fixate a point on a t r a n s l u c e n t screen during
Visual stimuli were projected onto the screen. 1. S p e c t r a l - s e n s i t i v e neurons,
They showed, besides w a v e l e n g t h - s e l e c t i v e
The properties of 489 neurons w h i c h made up 28% of the total
properties, a variety of c e n t e r - s u r r o u n d
i n t e r a c t i o n s w i t h i n h i b i t o r y or d i s i n h i b i t o r y e f f e c t s on center excitation, or with inhibitory effects from the center to the surround.
Such center-surround interaction could be of opponent or
of double o p p o n e n t type w i t h r e s p e c t to color.
2. F o r t y - t h r e e percent of the p r e l u n a t e neurons
were responsive to various spatial features without spectral sensitivity.
A special type within
this group was n e u r o n s w h i c h s t r o n g l y r e s p o n d e d to highly c o n t r a s t i n g stimuli. n e u r o n s w e r e r e s p o n s i v e to the internal s t r u c t u r e s of such stimuli. neurons were activated in connection with behavior. related to eye m o v e m e n t (1%). w i t h i n small,
irregularly
Many of these
3, T h r e e percent of the
4. Some of the activities of the neurons were
N e u r o n s w i t h spectral or n o n s p e c t r a l p r o p e r t i e s w e r e c l u s t e r e d
shaped patches,
p r e l u n a t e visual area is not a "colour area",
i - 4 m m in diameter.
It is c o n c l u d e d
that the
but r e s p o n d s to various features of the visual
environment and relates them, through its subcortical and cortical outputs, to behavior.
OF SINGLE FEATURES
NEURONS
IN T H E
INFEROTEMPORAL
CORTEX
OF T H E
MONKEY
SHIGERU YAMANE*, SHINJI KAJ!, AND KENJI KAWANO Electroteehnical Laboratory, Umezono, Tshukubashi, Ibarakiken 305, Japan Single neurons were recorded in the inferotemporal cortex (IT) of a monkey trained to discriminate three selected human faces from a large number of different faces (Neurosci. Res., s5, s114, 1987). We used 30 faces, a square and an ellipse as the discrimination stimuli, and also a small green spot that appeared after a stimulus disappeared to determine whether the monkey discriminated the stimulus or not. We examined 446 single neurons in the anterior and posterior banks of the superior temporal sulcus, including its fundus, and the gyrus of the IT. Of the 446 neurons, there were 86 face-responsive neurons. Most of them responded also to the green spot (41/86), and the square and/or the ellipse (24/86). These neurons were found in all regions. Out of 86 neurons, only 21 responded exclusively to the faces, and most of them (18/21) were located in the gyrus of the IT. Faces used as stimuli were quantified by measuring the distances between individual parts of the face e.g., eyes, eyebrows, nose, mouth, hair, etc. The correlation analysis between the quantified facial features and the response magnitudes gave correlation coefficients greater than 0.6 for five out of the 21 face-responsive neurons. Responses of these neurons correlated to the combined distances between the different parts of the faces. One of them showed correlated responses to the combination of the degree that the forehead above the left eye was covered with hair and the distance between the eyes and the mouth. In order to confirm that the neuron detected the combined facial features, six montaged faces made up of two faces, i.e., one face that excited and another that inhibited the neuron, were used as the stimuli. The relationships between the responses of this neuron to the montaged faces and the combined facial features were close to the regression line obtained from the correlation analysis. It is concluded that this neuron detected the combination of the degree that the forehead was covered with hair and the distance between the eyes and the mouth. The fact that the neuron detected essential features to faces confirms that the neuron belongs to face neurons. All of the face-responsive neurons that responded also to the square or the ellipse showed a correlation coefficient of less than 0.6 in our analysis.
VISUAL PROPERTIES OF NEURONS IN THE PRELUNATE VISUAL AREA.
TANAKA M A S A F U M I , C R E U T Z F E L D T OTTO D E T L E V *+, Dept. of A e r o s p a c e Physiology, Res. Inst. of Environmental Medicine., Nagoya Univ., Furo-cho, Chikusa-ku, Nagoya 464, TDept. of Neurobiology, Max-Planck Inst. for biophysical chemistry, P.O. Box 2841, 3400 Gottingen, F. R. Germany. We recorded a c t i v i t i e s from single neuron units in the p r e l u n a t e gyrus of two a w a k e m o n k e y s ( M a c a c a sylvana). recording sessions.
The m o n k e y s
w e r e divided into four groups: neurons.
w e r e trained to fixate a point on a t r a n s l u c e n t screen during
Visual stimuli were projected onto the screen. 1. S p e c t r a l - s e n s i t i v e neurons,
They showed, besides w a v e l e n g t h - s e l e c t i v e
The properties of 489 neurons w h i c h made up 28% of the total
properties, a variety of c e n t e r - s u r r o u n d
i n t e r a c t i o n s w i t h i n h i b i t o r y or d i s i n h i b i t o r y e f f e c t s on center excitation, or with inhibitory effects from the center to the surround.
Such center-surround interaction could be of opponent or
of double o p p o n e n t type w i t h r e s p e c t to color.
2. F o r t y - t h r e e percent of the p r e l u n a t e neurons
were responsive to various spatial features without spectral sensitivity.
A special type within
this group was n e u r o n s w h i c h s t r o n g l y r e s p o n d e d to highly c o n t r a s t i n g stimuli. n e u r o n s w e r e r e s p o n s i v e to the internal s t r u c t u r e s of such stimuli. neurons were activated in connection with behavior. related to eye m o v e m e n t (1%). w i t h i n small,
irregularly
Many of these
3, T h r e e percent of the
4. Some of the activities of the neurons were
N e u r o n s w i t h spectral or n o n s p e c t r a l p r o p e r t i e s w e r e c l u s t e r e d
shaped patches,
p r e l u n a t e visual area is not a "colour area",
i - 4 m m in diameter.
It is c o n c l u d e d
that the
but r e s p o n d s to various features of the visual
environment and relates them, through its subcortical and cortical outputs, to behavior.