Simple Detection Lab

Data:

Lab Questions

●        The reason my results of this lab were not instantaneous can be attributed to the processing time our brains require. Bottom-up processing explains perception when we receive stimuli from our environment (Goldstein, 2019). In this scenario, an image is seen on the retina, but the result of button-pressing cannot occur immediately because the brain has to process that information. Once the image is registered, it gets sent to the brain, which takes time (Goldstein, 2019). This is reflected in my 20 attempts to indicate recognition of the green dot as quickly as possible. I could not get less than 203 ms in the twenty times I tried.

●        The reason I cannot react faster than 200ms is because I’m human. Not only does the process of delivering the image to my brain take time, but my brain must also send a signal to my hand letting it know to press the button (Goldstein, 2019). This process of information relay from retina to brain and from brain to hand takes time. Therefore, it’s not likely for any human to get a score under 200 ms.

Signal Detection Lab

Data:

Lab Questions

●        When there is less noise in the images, it becomes easier to detect a target image as it stands out easier when there are less dots to distinguish. Another complication of identifying the target amongst noise could be attributed to the oblique effect. Shapes that are either vertical or horizontal are easier for humans to detect because these shapes appear in both nature and man-made objects than slanted shapes do (Goldstein, 2019). The target we are asked to search for is a diagonal line, which is naturally more difficult for us to detect. When we clutter the image with noise, it becomes even more difficult to identify it amongst scattered dots.

●        What does d’ measure and how is it calculated? Why is this a helpful tool when measuring cognitive tasks?

According to Goldstein (2019), the d’ measures our overall ability to decipher whether a target was present versus absent. Also, according to Goldstein (2019), the d’ is calculated by considering the amounts of hits a participant produced as well as the number of false alarms they produced; then comparing those numbers against one another to determine the participant’s personal measure of sensitivity. This is a helpful tool when measuring cognitive tasks because it allows us to consider the individual bias each participant has and allows us a means to control for their conservative or liberal tendencies within their responses.

Visual Search Lab

Data:

Lab Questions

●        Theoretically, the reaction time for the feature trials should not change as the number of distractors increases, regardless of whether or not the target is present (Goldstein, 2019). My reaction time increased slightly as the number of distractors increased, but I do not feel like the change was very significant. With conjunction trials, the reaction time should increase as the number of distractors increases because it takes time to scan the images and decipher a target (Goldstein, 2019). Further, the reaction time should be less when the target is present versus when it is absent due to the fact finding it results in a reaction and not finding it requires scanning of every image to determine absence (Goldstein, 2019). This is reflected in my response times as it took me longer to determine a target was absent than it took me to determine a target was present. Also, it took me significantly more time to find the target as the number of distractors increased in conjunction trials, whereas the change in time was less significant in feature trials.

●        An example of conjunction search in everyday life can relate to examining body language. If someone has their head in their hands, it could mean multiple things such as they’re stressed, overwhelmed, tired, or have a headache. It is the job of therapists to read this body language and deduct the reason for it using other contextual clues. Finding signs of distress amongst many distractors is a task that becomes critical in fields like psychology. Sometimes we might make a wrong assumption, but it’s important to recognize subtle signs amongst many distractions.

Module Question

In the simple detection task, the mind has the simplest job of perception- recognizing the presence of a target with no distractors present and signaling the hand to react to the target. For the signal detection task, the mind is required to perform more complex tasks of perception. Not only does it have to process that an image has been received, it also has to distinguish if a certain image is present amongst a clutter of similar images. In order to do this, the image first has to be received and then sorted to determine if a target is present. Once a decision has been made, the mind must relay the answer to the hand in order to react appropriately. Lastly, in the visual search task, the mind must complete the most complicated task of sorting. In this task, multiple images are sent to the brain, where it must determine if a certain shape of a certain color is present amongst other shapes and colors that may be similar or different. Once the brain has sorted these images and determined the presence or absence of the target shape, it must relay the information to the hand to react. The brain is an amazing and complex system capable of processing, sorting, and identifying information. Even though these processes take time, they are completed at rather remarkable speeds considering the amount of computing the brain must do between receiving an image and relaying a command. Although some humans may react and respond faster than others, all humans must take some time to process and relay information in their mind- it is not an instantaneous function for anyone, even when it may seem to be. 

References

Goldstein, E. B. (2019). Cognitive Psychology (5th ed.) Cengage. https://www.cengage.com/