Part Of: Object sequence
Content Summary: 400 words, 4 min read
Binding Via Phase Locking
As we have seen, objects are distributed networks: their resident features are computed in myriad locations across cortex.
The binding problem is: how do these distributed networks cohere? How does geographic division become logical unity?
Object binding seems to be accomplished via phase locking. By some unknown mechanism, firing patterns from disparate features synchronize, such that they all strike consumer processes simultaneously. By this temporal mechanism, objects increase their “firing power” while not needing to amplify their component signals.
Phase locking can be observed in the electrical rhythm of the brain, as measured by the electroencephalogram (EEG). Phase locking is only observed during the wakeful state, disappearing with the onset of Slow Wave Sleep (SWS).
We hypothesize that phase locking is necessary for object creation; that it is the solution to the binding problem. But phase locking only occurs during wakefulness. This suggests that object creation and consciousness are closely interrelated processes.
Let us conjecture that objects are the language of consciousness. They are the Song of Cortex.
This hypothesis provides explanatory firepower. We may now dissolve two Gordian knots.
The Unconscious Dorsal Stream
Remember blindsight? We explored blindsight in The Three Stream Hypothesis: blindsight patients have visual information accessible to the Dorsal Stream, but not the Lateral nor Ventral Stream.
But why should the Dorsal Stream be uniquely non-conscious? This is one of GWTs big open questions, as acknowledges by Baars in Global Workspace Dynamics, 2013. But we have made two conceptual moves that Baars has not:
- Objects are the language of consciousness
- Objects are created across by a ventral Classifer and a lateral Localizer engine (see Dual Engine Hypothesis, here).
The Dorsal Stream is unconscious because it does not participate in object construction.
In the working memory literature, chunking refers to the ability to retain more information via drawing creative boundaries around information. Suppose I were to verbally recite the following phone numbers:
Both sounds encode the same information, but you could remember the latter more easily. Why?
It is widely acknowledged that the contents of working memory are available to consciousness. If working memory is the Global Workspace, then we would expect that chunks are objects. And indeed, our conjecture does successfully explain chunking:
In the above example, we retain the chunked version better because it requires the activation of only three objects (206, 555, 1220), rather than ten, single-digit objects.
- Evidence of phase locking suggests that objects are the language of consciousness:
- Objects are created by two engines: a Localizer and a Classifier. The Dorsal stream contains neither engine, and is thus non-conscious.
- Objects explain working memory results such as chunking.