TY  - JOUR
A1  - Miller, Jeff
A1  - Schwarz, Wolfgang
T1  - Brain signals do not demonstrate unconscious decision making: An interpretation based on graded conscious awareness
JF  - Consciousness and cognition
N2  - Neuroscientific studies have shown that brain activity correlated with a decision to move can be observed before a person reports being consciously aware of having made that decision (e.g., Libet, Gleason, Wright, & Pearl, 1983; Soon, Brass, Heinze, & Haynes, 2008). Given that a later event (i.e., conscious awareness) cannot cause an earlier one (i.e., decision-related brain activity), such results have been interpreted as evidence that decisions are made unconsciously (e.g., Libet, 1985). We argue that this interpretation depends upon an all-or-none view of consciousness, and we offer an alternative interpretation of the early decision-related brain activity based on models in which conscious awareness of the decision to move develops gradually up to the level of a reporting criterion. Under this interpretation, the early brain activity reflects sub-criterion levels of awareness rather than complete absence of awareness and thus does not suggest that decisions are made unconsciously.
KW  - Neuroscience
KW  - Consciousness
KW  - Decision making
KW  - Libet
Y1  - 2014
U6  - https://doi.org/10.1016/j.concog.2013.12.004
SN  - 1053-8100
SN  - 1090-2376
VL  - 24
SP  - 12
EP  - 21
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - INPR
A1  - Schwarz, Wolfgang
A1  - Miller, Jeff O.
T1  - When less equals more: probability summation without sensitivity improvement
T2  - Journal of experimental psychology : Human perception and performance
N2  - Many perceptual and cognitive tasks permit or require the integrated cooperation of specialized sensory channels, detectors, or other functionally separate units. In compound detection or discrimination tasks, 1 prominent general mechanism to model the combination of the output of different processing channels is probability summation. The classical example is the binocular summation model of Pirenne (1943), according to which a weak visual stimulus is detected if at least 1 of the 2 eyes detects this stimulus; as we review briefly, exactly the same reasoning is applied in numerous other fields. It is generally accepted that this mechanism necessarily predicts performance based on 2 (or more) channels to be superior to single channel performance, because 2 separate channels provide "2 chances" to succeed with the task. We argue that this reasoning is misleading because it neglects the increased opportunity with 2 channels not just for hits but also for false alarms and that there may well be no redundancy gain at all when performance is measured in terms of receiver operating characteristic curves. We illustrate and support these arguments with a visual detection experiment involving different spatial uncertainty conditions. Our arguments and findings have important implications for all models that, in one way or another, rest on, or incorporate, the notion of probability summation for the analysis of detection tasks, 2-alternative forced-choice tasks, and psychometric functions.
KW  - probability summation
KW  - compound detection or discrimination
KW  - redundancy gain
KW  - ROC curve
KW  - 2AFC
KW  - psychometric functions
Y1  - 2014
U6  - https://doi.org/10.1037/a0037548
SN  - 0096-1523
SN  - 1939-1277
VL  - 40
IS  - 5
SP  - 2091
EP  - 2100
PB  - American Psychological Association
CY  - Washington
ER  -