Neuroscience
As soon as we know something is there, we already know what category of thing it is. That's according to Kalanit Grill-Spector and Nancy Kanwisher at Stanford University and MIT.
They showed people images for between 17 to 167ms, some of which contained an object - a jeep or a German shepherd dog, for example - some of which just showed an incoherent scramble of images. Sometimes participants had to say as fast as they could whether an object was present or not ('detection'), other times they had to indicate what category the object belonged to (e.g. a car or a dog), other times they had to identify the object specifically (e.g. to indicate as fast as possible whether or not the object was a German shepherd dog, for example).
People took no longer to categorise an object than they took to detect whether an object was present or not. Moreover, on trials when categorisation performance failed, detection performance was no better than chance, and vice versa, thus suggesting the processes were mutually dependent on each other. This has important implications for theories of visual object recognition. It suggests that segmentation of a visual scene into background and foreground, needed to detect objects, occurs at the same time as object categorisation. Either that, or conscious awareness only kicks in after the categorisation stage.
However, identifying an object took longer by about 65ms, suggesting object identification occurs only after its category has been determined.
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Grill-Spector, K. & Kanwisher, N. (2005). Visual recognition. As soon as you know it is there, you know what it is. Psychological Science, 16, 152-159.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
Seeing what things are
As soon as we know something is there, we already know what category of thing it is. That's according to Kalanit Grill-Spector and Nancy Kanwisher at Stanford University and MIT.
They showed people images for between 17 to 167ms, some of which contained an object - a jeep or a German shepherd dog, for example - some of which just showed an incoherent scramble of images. Sometimes participants had to say as fast as they could whether an object was present or not ('detection'), other times they had to indicate what category the object belonged to (e.g. a car or a dog), other times they had to identify the object specifically (e.g. to indicate as fast as possible whether or not the object was a German shepherd dog, for example).
People took no longer to categorise an object than they took to detect whether an object was present or not. Moreover, on trials when categorisation performance failed, detection performance was no better than chance, and vice versa, thus suggesting the processes were mutually dependent on each other. This has important implications for theories of visual object recognition. It suggests that segmentation of a visual scene into background and foreground, needed to detect objects, occurs at the same time as object categorisation. Either that, or conscious awareness only kicks in after the categorisation stage.
However, identifying an object took longer by about 65ms, suggesting object identification occurs only after its category has been determined.
________________________________
Grill-Spector, K. & Kanwisher, N. (2005). Visual recognition. As soon as you know it is there, you know what it is. Psychological Science, 16, 152-159.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Human memory capacity is many orders of magnitude more impressive than previously realised, psychologists have shown (the study can be accessed for free). Timothy Brady and colleagues presented 14 participants with 2,500 mundane objects, presented one...
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Imagine you knew the answer to a question but the only way you could retrieve it was to draw the solution on a piece of paper. That's exactly what can happen when people are asked to close their eyes and identify a drawn object using only their fingertips...
- Judging What Came First
You can’t possibly process everything that’s going on around you. Instead you’re armed with an attentional spotlight that selects areas and objects of interest for preferential processing. An anomalous consequence of this, is that we judge objects...
- Whitney Diane Sawyer Skit
The brilliant Debra Wilson as Whitney Houston. Fast forward to 2:30 to hear the famous lines....
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The Cambridge Car Memory Test: A task matched in format to the Cambridge Face Memory Test, with norms, reliability, sex differences, dissociations from face memory, and expertise effects Behav Res Methods. 2011 Oct 20; Dennett HW, McKone E, Tavashmi R,...