BIO - Hormones & Pheromones

Hormones

Chemicals released by specific glands in the body to regulate medium- and long-term changes in the body

They are released directly into the bloodstream, yet hormones may act as neurotransmitters and attach to post-synaptic receptor sites when they act on the brain

Our chosen hormone

Adrenaline

Cortisol in threatening scenario

Hypothalamic-pituitary-adrenal axis – or HPA axis.

Stimulus threat → hypothalamus responds by activating pituitary gland → releases a hormone that activates the adrenal glands→ cortisol is released into the bloodstream. 

Cortisol dumps glucose into your bloodstream to provide energy — important part in the ‘fight or flight’ response. (Help humans survive in the face of danger so that they can quickly escape an immediate threat)

Hormones - Study

McGaugh & Cahill (1996)

McGaugh & Cahill (1996) AIM

To study the role of adrenaline in the creation of memories.

McGaugh & Cahill (1996) PROCEDURE

PPs were administered a beta-blocker called propranolol or a placebo.

PPs saw 12 slides with a story.

1. Woman and her son who visit the son’s father in a hospital where they witnessed the staff in a disaster preparation drill of a simulated accident victim.

2. The boy was in a car accident where his feet were severed. In the hospital, surgeons reattached the limbs. He stayed in the hospital for a weeks and then went home with his mother.

Afterwards, PPs answered how emotional they found the story (1 - 10).

Two weeks later, PPs answered recognition task. It consisted of a series of questions about the slides with three options for them to choose from. E.g. what was the job of the father of the boy in the story? A, B, C

Propranolol effect

Blocks target cells for adrenaline so that the heart will pump more slowly and efficiently. This was used to prevent activation of the amygdala.

McGaugh & Cahill (1996) RESULTS

Those who had received the beta-blocker did no better than the group that had heard the "mundane" story.

McGaugh & Cahill (1996) FINDINGS 

The amygdala plays a significant role in the creation of memories linked to emotional arousal.

Pheromone

A secreted or excreted chemical factor that triggers a social response in members of the (usually) the same species. In humans, they are called PUTATIVE CHEMICAL CUES, as scientists have yet to identify any human pheromones or a way to process them

Our chosen pheromone

(Androstadienone) AND - male semen and sweat

(Estratetraenol) EST - female urine (female equivalent of the steroid)

Androstadienone (AND)

Effect on attraction however not overtly.

Heightens sympathetic arousal, alters levels of cortisol, and promotes a positive mood state in females.

Activate the hypothalamus in those attracted to males.

Pheromones limitation

Humans lack a functional vomeronasal organ [VNO] and an accessory olfactory bulb [AOB].

Without anatomical ability to detect the pheromone, it is unclear how a pheromone would affect human behavior.  

Pheromones - Study

Zhou et al. (2014)

Zhou et al. (2014) AIM

To investigate the effect of AND and EST on heterosexual and homosexual men and women

Zhou et al. (2014) PROCEDURE

Sample: 4 groups of 24 of homo or heterosexual men or women

Ps watched stick figures walking on a screen and determined their gender - called teh point light walker tas (PLW). Simultaneously exposed to the smell of cloves. there wer ethree conditions

1) And

2) Est

3) Control

Counterbalancing was donen to control for order effects

Zhou et al. (2014) RESULTS

Attracted to men + AND = higher rate of identifying the stick figure as “masculine” than CG. 

AND had no significant effect on those attracted to women

Hetero MALE were exposed to EST = biased toward perceiving the walkers as more feminine.

The effect was NOT statistically significant in homo FEM.

Zhou et al (2014) FINDINGS

AND and EST may have some effect on human sexual behavior.

The researchers concluded that pheromones influence the communication of gender information in a sex-specific manner.