The Journal of Neuroscience, September 5, 2007, 27(36):9632-9637; doi:10.1523/JNEUROSCI.2734-07.2007
Previous Article | Next Article 
Behavioral/Systems/Cognitive
Spatial Attention and the Latency of Neuronal Responses in Macaque Area V4
Joonyeol Lee,1
Tori Williford,1 and
John H. R. Maunsell1,2
1Department of Neuroscience and 2Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030
Correspondence should be addressed to John H. R. Maunsell at his present address, Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115. Email: maunsell{at}hms.harvard.edu
The effects of attention on neuronal responses in visual cortex have been likened to a change in stimulus contrast. Attention and stimulus contrast both modulate the magnitude of neuronal responses. However, changes in stimulus contrast also affect the latency of visual responses. Although many neurophysiological studies have examined how attention affects the strength of neuronal responses, few have considered whether attention affects neuronal latencies. To compare directly the effects of stimulus contrast and attention, we recorded responses from individual neurons in area V4 of macaque monkeys while they performed a task that independently controlled spatial attention and stimulus contrast. As expected, changes in stimulus contrast affected both the magnitude and latency of neuronal responses. Although attention had the expected effects on the magnitudes of neuronal responses, we did not detect statistically reliable changes in neuronal latency. A direct comparison of the effects of contrast and attention revealed a reliable difference. When a shift in spatial attention decreased response magnitude, response latency increased much less than when the same magnitude change was caused by reducing stimulus contrast. Thus, attention is distinct from contrast in the way it affects the relationship between neuronal response magnitude and latency.
Key words: attention; latency; contrast; area V4; single-unit; macaque
Received June 15, 2007;
revised July 19, 2007;
accepted July 20, 2007.
Correspondence should be addressed to John H. R. Maunsell at his present address, Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115. Email: maunsell{at}hms.harvard.edu
Related articles in J. Neurosci.:
- Turning on the Spotlight: Do Attention and Luminance Contrast Affect Neuronal Responses in the Same Way?
- Michael J. Proulx
J. Neurosci. 2007 27: 13043-13044.
[Full Text]
This article has been cited by other articles:

|
 |

|
 |
 
M. CARRASCO, S. FULLER, and S. LING
Transient attention does increase perceived contrast of suprathreshold stimuli: A reply to Prinzmetal, Long, and Leonhardt (2008)
Percept Psychophys,
October 1, 2008;
70(7):
1151 - 1164.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
C. I. Buia and P. H. Tiesinga
Role of Interneuron Diversity in the Cortical Microcircuit for Attention
J Neurophysiol,
May 1, 2008;
99(5):
2158 - 2182.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Li and M. A. Basso
Preparing to Move Increases the Sensitivity of Superior Colliculus Neurons
J. Neurosci.,
April 23, 2008;
28(17):
4561 - 4577.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. J. Proulx
Turning on the Spotlight: Do Attention and Luminance Contrast Affect Neuronal Responses in the Same Way?
J. Neurosci.,
November 28, 2007;
27(48):
13043 - 13044.
[Full Text]
[PDF]
|
 |
|
eLetters:
Read all eLetters
- Attention vs. Contrast for the Single Neuron: Does the Analogy Hold?
- P.Christiaan Klink
- J. Neurosci. Online, 16 Nov 2007
[Full text]