© Φ Philosophical Writings
Proceedings of the Fifteenth Annual British Postgraduate Philosophy Conference
TYPE-2 BLINDSIGHT, SELF-
ATTRIBUTION AND QUALIA:
A PROBLEM FOR QUALIA-BASED
ACCOUNTS OF BLINDSIGHT
Robert Foley – University College Dublin
Abstract
Type-2 blindsight is a phenomenon in which a patient with blindsight reports
some awareness corresponding to the presentation of stimuli in their
scotoma, without this awareness being a normal experience of those stimuli.
Recent research into type-2 blindsight has raised many interesting questions
for philosophical debates about consciousness. In this paper I argue that
blindsight, as it is traditionally understood (e.g., Weiskrantz, 2008), cannot
properly incorporate type-2 blindsight. This has resulted in type-2 blindsight
often being treated as a peripheral phenomenon. I discuss a recent study in
which a blindsight subject (GY) reported on his visual experiences in his
scotoma under type-2 conditions. I argue that traditional accounts of
blindsight cannot explain GY’s reports, and that his reports also raise serious
issues for those who wish to defend a standard notion of qualia. In particular,
the case puts pressure on two major tenets underlying the notion of qualia
(the ‘constitutive claim’ and the ‘revelation thesis’). It is argued that those
who wish to defend qualia must reject one or other of these tenets in the face
of evidence from GY’s first-person reports.
Introduction
The canonical definition of ‘blindsight’, as given by Lawrence
Weiskrantz, is “visual capacity in a field defect in the absence of
acknowledged awareness.”
1
Weiskrantz and others noted, in early studies,
that the blindsight subject ‘DB’ often had some form of awareness of
high-contrast or moving stimuli in his blind field. This became known as
type-2 blindsight: when a patient with blindsight (as defined above)
reports some awareness corresponding to the presentation of stimuli in
their scotoma, but without this awareness being a normal experience of
1 Weiskrantz (1986), p. 225.