News
Dr. Chris Striemer receives a Board of Governors Research Chair from MacEwan University. [posted August 26, 2021]
Dr. Chris Striemer has received a Board of Governors Research Chair from 2021-2023. Click here for the full story.
New review chapter on Blindsight. [posted Jan 27, 2021]
We recently published a review article on Blindsight in the Handbook of Clinical Neurology that summarizes both early and recent work on the topic and reviews the neural pathways that may be responsible for different forms of Blindsight.
Dr. Chris Striemer wins MacEwan's 2020 Distinguished Researcher Award. [posted Jan 27, 2021]
APA lab's own Dr. Chris Striemer received the 2020 MacEwan Distinguished Researcher Award.
Visuomotor adaptation does not require conscious visual input. [posted Feb 5, 2019]
In a paper that was just accepted in Cortex we demonstrated that patient MC - who is completely cortically blind following extensive lesions to V1 and early ventral stream regions - was still able to adjust her movements in response to a prism induced visual shift. Specifically, for each prism shift (i.e., left vs. right) by hand (i.e., left vs. right) combination tested MC showed evidence of "strategic recalibration" by reducing her pointing errors by the same magnitude as controls. In addition, MC also demonstrated "spatial realignment" such that her reaches were shifted in the direction opposite the prisms following adaptation. This is the first clear demonstration that conscious visual input from early visual cortex is not required for visuomotor adaptation to occur. Instead, we hypothesized that MC was able to adapt to prisms based on non-conscious visual information relayed to the cerebellum through well-known connections with the motion sensitive regions MT and STS, as well as dorsal stream regions in the posterior parietal cortex, via the dorsolateral pons.
Media release related to our recent work with affective blindsight. [posted Feb 5, 2019]
Here is a link to a media release from the Canadian Institute for Advanced Research (CIFAR) on our recent publication in Neuropsychologia examining affective blindsight in a patient with complete cortical blindness.
https://www.cifar.ca/cifarnews/2019/02/01/woman-who-is-blind-can-see-emotions
Affective blindsight does not require input from face processing regions in the ventral visual pathway. [posted Nov 16, 2017]
In our most recent work published in Neuropsychologia (reprint below) we studied non-conscious emotion discrimination in patient (MC) who is completely cortically blind to static (i.e., non-moving) stimuli following bilateral damage to her occipital-temporal cortex including core object (i.e., LOC) and face processing regions (i.e., FFA and OFA). Despite these extensive lesions MC was still able to discriminate between different facial emotions. Specifically, patient MC was better than chance at determining whether a face was "happy" vs. "fearful" and "happy" vs. "angry" even though she insisted that she "saw nothing" and was "completely guessing." MC's inability to perceive the faces was further reinforced by the fact that she was at chance at determining whether the same faces were male or female. Taken together, these results provide direct evidence that affective blindsight (i.e., the ability to process facial emotions in the absence of visual awareness) can occur without input from object and face processing regions in the ventral visual pathway.
Prism adaptation speeds reach planning in the direction of the prism after-effect. [posted Jul 17, 2017]
In our latest paper currently in press in Experimental Brain Research (see file below for the accepted version) we demonstrate that prism adaptation can speed reach planning in the direction of the prism after-effect. This is yet another demonstration of how prism adaptation can have measurable effects on tasks that require motor responses with the adapted hand. In addition, we argue that prism adaptation might be useful for treating directional hypokinesia (i.e., slowed leftward movements) in patients with right brain damage.
The role of non-conscious vision in obstacle avoidance. [posted Apr 12, 2017]
In a recent paper in the journal Cortex Ross et al. (2016) published what essentially amounts to a failure to replicate our earlier 2009 findings in which we demonstrated that a patient with blindsight was able to avoid unseen obstacles in his blind field. In a Commentary that is currently in press in Cortex we critically re-analyze Ross et al.'s (2016) findings with a specific focus on the patient group they used, and the methods they employed. Based on this re-analysis we argue that the patients they used, and the methods they employed, nearly guaranteed that they would obtain the null result that their entire argument hinges upon. If fact, instead of being a "failure to replicate" we argue that their findings provide partial support for our initial conclusion, namely, that the dorsal visual stream is required for non-conscious obstacle avoidance. You can see our Commentary here or view the pre-print below.